I'm going to need both and eventually you will make both cases.
(Don't kill me for what i'm getting ready to say BadChad and Azarkhel

)
Even though i'm more excited about the prospect of Genesis cases, i think you will make your money back faster with NES cases. The most common complaint about UGCs for housing NES games is the legwork of modifying the cases. I would imagine NES covers/cases are one of the best sellers on Shadowfox's site. I believe he could make his money back quicker by selling the NES cases to our community AND the customers that visit his site.
Its no secret NES collecting is more prominent than Genesis collecting. I'd rather see NES cases w/ Shadowfox selling out in 2 months ready to move on the Genesis cases than making Genesis cases first and having to wait 5 months.
Food for thought
EDIT: I started writing this before Shadowfox put up the latest results from the poll. It looks like my prediction seems to be correct
