So I decided to write my own version of the S2HD engine instead of waiting for anything to come from LOst and company, and here's the result.
(click for full-size 1024x768 screenshot)
Emerald Hill Zone and Hill Top Zone are currently fully playable, including bosses.
I've only compiled a Windows version right now, since I had some issues with my Ubuntu 8.04 VM. Source code will be posted this weekend.
Download:
s2hd_alpha_release_0.4.zip (45.94 MB)