I always seemed to have things on my To Do List that I just never wanted to do. They'd weigh on me to the point I'd do anything but work on the game. The only way I found to get past it was to make a start on whatever it was, no matter how small - like, even just make the source files for the feature. Once *something* had been done it got incrementally easier to summon the energy to work on it.. The How To Play screens in Chopper had been on the To Do List since late last year for example...
Once I had finished whatever was getting me down it was a massive relief!
tldr; just do something!
Also, try to keep a variety of things on your To Do List so there's always a rewarding little thing to work on when you need a "I did something new" fix. Development momentum is super important!
Double-also: I really dislike the iPhone 4. 4S is great, but you can't drop support for the 4 on its own.. Chopper Mike has passed submission though, so Apple are cool with not supporting the 3GS/iPad1, and the game running 30fps on iPhone4 and 60fps on 4S/5/iPad2 etc...
In other news: Chopper Mike has been approved and will be on sale on Friday!