I don't care how long it takes for them to finish/release it. Heck, I'd probably be fi.ne if they decided to release it mid-august even.
As long as it can play the following, I'm happy
-Brutal Mario (SMW Hack)
-VIP Mario Series (SMW Hack)
-SMB3X (SMW Hack)
-The Second Reality Project (SMW Hack)
-*Insert long list of other SMW hacks here*
-Legend of Zelda: A Link to the Past (Without any Layer or GFX Issues)
-Chrono Trigger (Without any Layer or GFX Issues)
-Earthbound
-Secret of Mana (Without any Layer/GFX Issues)
-Secret of Evermore (Without any Layer/GFX Issues)
-Super Mario All Stars (Without any Layer Issues)
-Super Mario World (Without Layer/GFX Issues)
-Megaman 7 (Without any Layer/GFX Issues)
-Megaman X, X2, X3 (Without any Layer/GFX Issues)
-Legend of Zelda: Parallel Worlds (LTTP Hack, Without any Layer/GFX issues)
-Final Fantasy 3 (6 on the GBA, I had almost forgotten about this one)
-Final Fantasy 4
-Final Fantasy 5
-Kirby Super Star
-Kirbys Dream Land 3
If it can play these, then extra props.
-Super Mario RPG
-Star Fox
-Star Fox 2
As for the GUI, I'm not sure why a simple gui wouldn't work. I mean we don't really need it to be too fancy, do we. We're not really going to be looking at the SNES Emu's menu constantly instead of playing SNES games. As far as I'm concerned, they could use a simple GUI similar to that of Lameboy or something. Just as long as it's functional, that's really all that matters.
Course, if they are already making a fancy GUI, then that's fine too.
Actually, the funny thing is. If Super Mario RPG works, then there's a good chance that 90% of other games will work as well.