Feel your pain, man. Got the same thing, the only difference is that I didn't do jack about it, didn't click "de-authorize" cause I kinda smelt what the outcome would be.
Didn't even realize that no new app could be synch'ed with my mbp. But you know what, I don't really care for now. Pros and Cons, hell, having a working whatsapp on my iPad beats being able to synch any of my new apps with my computer (my bro lives 5500 miles away, Whatsapp helps a lot). Come to think of it, provided that the iTunes Store keeps close tab of my purchasing history in case I have to reinstall iOS, I don't even see why I'd need to synch any of my new apps with my computer.
That is, untill iOS5 and their iMessaging thing comes out. That'll replace whatsapp for me.