OK, let me give it a shot....

1. Banks go the way of Newspapers.
They won't disappear, but they change focus to value-added services like lending, intermediation and lose their current massive scale. Many disappear or break up, the most flexible go online for everything and start going after clients in a global way. In 2025 surviving banks are more like those newspapers that have survived the blogging revolution: different business model, focus on quality and brand-recognition and permanently aware that there are a million alternatives out there ready to eat their lunch if they don't treat clients well.

2. Central banks go the way of the Postal Service.
They will still exist, still think that they matter and still perform some functions... but their influence will be hugely reduced. They will be almost universally ignored... just the same way as central bank presidents in dollarised Latin American countries just focus on supervision and fraud prevention and have little to say on monetary policy. In 2025 they will still be able to move interest rates and do QE... but the ease of capital flight to quality and yield will mean that they cannot use these tools as freely as they do now for fear of seeing an immediate reaction in the FX/Crypto markets which negates their intended effects.

3.Taxes will trend to fee-for-services and real estate.
As capital becomes more mobile and it becomes ever easier to escape tax-heavy jurisdictions, governments will tend to tax more heavily assets that cannot be moved (real estate) and also services that they provide (toll-road model). Tax competition will increase... countries and cities will try to become attractive for investors and residents through lower taxes and more choice. The world will look a bit more like Swizerland where taxes are mostly collected and spent at the Canton (regional) level.

4. Africa will become much richer.
As millions of people can suddenly interact directly and get paid by employers in the developed world or receive remittances from their families at zero cost and without their local governments easily confiscating them. Anyone with technical and language skills in Africa who can get online will suddenly be able to compete with US and European workers for jobs and wages. In 2025 people living in extreme poverty will be less than 5% of the world population.

5. More Peace.
The increased difficulty in collecting taxes or printing money for unpopular causes like war will mean that wars last less and are more limited in the harm that they do. We will see tax revolts as a form of anti-war protest, with millions of people refusing to pay VAT or income tax until the government listens to their cries for peace, and unable to do anything to persecute such a large passive, peaceful resistance movement.

6. Technological Renaissance.
As capital accumulation in the technology sector grows and is less stifled by taxes, regulations and monopolies... investment in R&D grows and the rate of technological advance increases. Technological and economic growth see exponential rates last seen in the Industrial Revolution or the Renaissance.

How very ignorant. If you don't know what it is and want to learn then you have to start somewhere.

We all knew nothing at one point in time...

I read some of the comments. I never understood why people claim that obfuscation cannot add entroppy to the entire system. For example, if there are only 2 methods of obfuscation known to man then using one of them to further obscure your passphrase would add 1 additional bit of entropy.

Nice.  Did you ever figure out the dead man drop?
I have my own idea on that one. 

I appreciate your thoughts and nod, nod and agree. you solved the pruning risk elegantly (keeping a copy of the block which contains my proof of existence tx), argument about keeping the document so why not bundle it with support data, it all makes perfect sense and I will adopt it in my argumentation as viable options of doing things.

as for keeping the document secret, that is ok 'cause my use case is about testaments and using rather higher fee but satoshi tokens for the stamping. now it can be reversed, using old coins, zero fees and spending them afterwards as usual.

how trezor fits here nicely is to sign message that describes the signing/timestamping with an address that would be used to actually timestamp a document. so that it all can be verfied in one eintopf of documents and signatures that are loosely related but can reveal much more info if the right off-blockchain data is added to it and is examined.

To prove your pdf existed, I would go a similar route as you took: I would hash the doc, convert the private key to an address and verify that the address has received money in the past. If it has, either the document must have existed or the extremely unlikely event that someone chose the hash of the document as a private key by accident must have happened. Since we can rule out the latter with high probability, the documents existence at the time of the transaction is proven.

Please note: you should move the money from that address. Anyone with the document can access it.

http://www.proofofexistence.com/ might be what you're looking for. At least it's very similar (identical in function, I think) to what dnaleor is describing and what I had implemented for proving cascascius coin existance. btw, no invention there: I just used the sha256 of the document as a private key (there's no conversion, both are just a 256 bit numbers), derived the matching bitcoin address and sent money to it. Adavantage: you can still move that money. Disadvantage: you can't read any 'message', just verify it has existed if you have it.

"Is there a way to include a message in a signed bitcoin transaction?" <- I'm not sure what to make of this. You can sign a transaction, you can sign a message. You can encode a message into a transaction.

From memory:

Click on the account that you want to use. Then near the top right you will see a sign and verify button. Click it. It will bring up 2 forms that you can fill out, sign and verify. The first field will be the message. Enter the message that you want to sign in the message field. The second field will be the address. begin typing the address that you want to use. it will detect the address you are entering and provide an option to fill out the rest of the address for you. Click sign. Now look at your trezor. It will ask you to confirm that you want to sign the message. Confirm that you do. Now enter your pin. Look back at the form page in your browser. you will see that the formerly empty signature box will now contain a series of characters. That is your digital signature.