I don't really understand why people freak out about Blockchain.info going away. I don't know if I configured it this way, but every time I make a change to my wallet (i.e. add a new address, etc), they send me an encrypted json file with all the info I need to restore my wallet elsewhere. What you should be more worried about is Blockchain.info's login screen being compromised to capture your password as you log in. (That's the element of trust involved with using their service.)

[edit]Hmm. So, since I last checked, it seems Multibit has removed the functionality from their app. So I guess we are semi-screwed if Blockchain.info went down to restore our wallets elsewhere. (I'm not sure I have the programming chops to back the wallet decryption functionality out of the Blockchain.info source code on github....)