Here are my brainstorming ideas I've had over the past few days. I had the old foundation thread open since this morning, posted in it, and THEN I saw this thread. I just went and deleted my other post and decided to bring it here.
I remember reading something about protecting a coin from a 51% attack by bookmarking the blockchain before the attack started. What if this new chain had automatic, even hourly, bookmarks/checkpoints. Should someone start up a 51% attack, just wait until it's over and revert to before the attack started.
One of the things that has made Litecoin so popular is the quick transaction confirmations. I think a new coin should be able to match or even beat LTC. (Maybe 2 minute intervals instead of LTC's 2.5?)
I think it should definitely be a more CPU-friendly coin. A lot of computers come with nicer dedicated graphics now, but higher end cards still blow these out of the water. If a GPU friendly coin was launched, it could easily be taken over by current BTC miners or ASICs. CPU-friendly coins more or less level the playing field, but, as mentioned, are vulnerable to botnet attacks. This is where the checkpoint system comes into play.
I don't know if a checkpoint system is the definitive answer to 51% attack protection, but there should be some sort of way to protect from 51% attacks. The coin I was thinking about looking into developing I wanted to call APC, or ArmoredCoin, or something along those lines, signifying it's strength and protection.
As for the amount issued, maybe follow this example: BTC is gold, LTC is silver, this new coin could be the copper equivalent. Issue 10x total amount relative to Bitcoins, and then make these coins worth 1/10th of a BTC once they become established.
I had a few other ideas, but this is all that comes to mind at the moment.