I think it should be enough to backup your wallet, delete your .bitcoin folder in your user profile folder, create a new .bitcoin folder, put your wallet inside and then start bitcoin. It should download a new copy of the block chain and you should be good to go. AFAIR this is a known bug.
Don't do that, you'll just spend a lot of time re-downloading the block chain and then be back in the same state you were before (unless you happen to get lucky and your transactions get confirmed while you're waiting for the block chain to download again).
Restarting bitcoin and letting it get 8 fresh connections might help. Allowing incoming connections so you have more than 8 connections should also help your transactions get confirmed.
Safest thing to do is to be patient; your transactions will be rebroadcast and eventually will get confirmed. If they're not confirmed in a week, then there are ways of deleting the transactions from your wallet and "freeing up" the stuck bitcoins, but messing with your wallet should always be a last resort.
