There was a large spam influx at the end of last week, thankfully the moderation settings stopped the forum from being visibly flooded. Unfortunately I had to automatically delete users created after a certain date, so if you signed up recently and are wondering where you account went, sorry - please register again and I'll make sure it gets accepted quickly!
I've also changed the anti-spam question in an attempt to prevent future spam signups. It should be relatively obvious if you've bought Desktop Dungeons (or search where to buy it).