I was putzing about the 'net yesterday and thought I'd wander on over to the Metroid Database because I haven't been there in a while and I happened upon this news article. Apparently some previously unknown ROMhacker going by the moniker "SB" has created a Zero Mission style hack out of the SNES Super Metroid ROM. I tried it out last night and it's basically exactly what I hoped it would be...a Metroid 1 remake using Super Metroid as it's engine, with Zero Mission style graphics, Super Metroid style sprites, and a map layout reminiscent of the original Metroid. The overall level design so far seems to be tighter than security at Fort Knox, although I'm currently having a lot of trouble progressing in the hallway leading to the bombs. Nonetheless, I'd highly recommend checking this out if you happen to be a Metroid-phile. This seems to be a pretty amazing ROMhack by all standards.
Cheers and happy exploring.