Well i was looking at the blizzard site and i found this. Their is a chance your server list has been changed by you accidently or someone else spyware/virus whatever. But read this and download the battle net server list fix and follow the instructions their. Also give a reinstalling a shot. Can you play other games online Counter Strike etc.
No problem man, try go through all those six steps they give for problems connecting to battlenet and also i saw that u can send them an email or something and get professional help, but i hope it doesnt come to that.