You know what... I actually think that
does look a bit nicer than the blurry mess I created. I'm quite sure I originally tried the exact method you have used, and just didn't like the way it looked... But it seems now I do.
Of course, that could just be due to me currently viewing your design on my phone, which has a particularly nice screen.
At any rate, I might have to play with the simple 2bpp version again now, just to see where I currently stand on the issue.
Either way, I suppose the good news here is that I will eventually make multiple versions of each background (and perhaps foregrounds, etc.) available for people to choose between. When that system's in place, hopefully everyone can find a look they enjoy.
As for the parallax suggestion; I've certainly given it some thought in the past, and now might be the perfect time to try a few techniques out. Thanks for the nudge; expect a demo to try out soon.
Edit #2: So glad you're loving the CSS3 efforts! I completely agree with you that they inject a lot of life into these maps, and although it can be a slow process getting them looking just right, I think the end result makes it all worthwhile.