This just happened to me today for the first time. In my case I just watched the escapist video about cataclysm and got really excited to see what was going on. So I hopped on battlenet and resubscribed. I opened up the WoW updater and let it do its thing till it was ready to play. Now it was time to get in some WoW for the first time in like 4 months. Fuuuuuck! It's Tuesday morning!