I am not a technical guy, but I know there will be more and more project based on bitcoin protocol. We are happy to see that there are more and more bitcoin protocol application startups. Never think Bitcoin is just a kind of crypto-currency, bitcoin is more than a crypto-currency. Lots of application could be coming out above the protocol. I would like to list the potential project here:

1. MSC - Mastercoin, application on top of bitcoin protocol(http://www.mastercoin.org/, http://masterxchange.com/, https://masterchain.info/, https://masterchest.info/)

2. Coloredcoins, application on top of bitcoin protocol(http://coloredcoins.org/, http://chromawallet.com/, https://bitcointalk.org/index.php?topic=106373.msg3864913#msg3864913)

3. BTS - Bitshares, new application(http://invictus.io/, https://bitsharestalk.org/index.php)

4. NXT - Nextcoin, new application totally different than bitcoin(https://nextcoin.org/index.php, http://www.nxtcrypto.org/, https://bitcointalk.org/index.php?topic=345619.0)

5. XCP - Counterparty, application on top of bitcoin protocol(https://bitcointalk.org/index.php?topic=395761.0, http://counterparty.co/)

6. eMu - eMunie, new application totally different than bitcoin(http://emunie.com/)

7. eTher - ethereum, application on top of bitcoin protocol(http://ethereum.org/, https://bitcointalk.org/index.php?topic=412878.0, http://ethereum.org/ethereum.html)

8. Zerocoin, new application totally different than bitcoin(http://zerocoin.org/, http://zerotrade.org/, http://www.forbes.com/sites/andygreenberg/2014/01/13/bitcoin-anonymity-upgrade-zerocoin-to-become-its-own-cryptocurrency/)

If you know more, follow this thread.