..I can tell you why you should get E410..
+ compressed RAW - 11MB vs. 22MB is a quite huge difference
+ better battery runtime - additional 100+ photos but there are some early reports about 1000+ images from a single battery charge!!!!
+ even better noise performance - almost no visible noise at ISO1600 with still preserved details! Many non-Oly people says, it's even better than some Canon and most of all Nikon models!
+ selectable noise filter - if you are like me, who like to turn the noise reduction/filter completely OFF
+ mirror lockup - yep missing in E400!
+ turnable Flash AF Illuminator - so you can have raised flash without distracting and almost useless AF Illumination.
+ LiveView - I personally don't care about this. In daylight is still better to use viewfinder with split focusing screen
I think, all these additional features and improvements are worth of $100 and I have some hard time to decide to sell or keep the E400 and buy the E410 body

I simply love the E4xx concept so E410 is very tempting for me.