non-gravity on 25 July 2009
DSi should not cost 100$ more than the DS Lite more like 20-30 more
I don't think you can install UMD onto a memorystick (which you'll first have to buy)
Sony are trying to get as many games available for digital distribution, and most games will, but I'd guess there will be games UMD only. (though there also are a few games that were not released on UMD and only available in the PS Store)
