20101224 is out now, with a fair number of changes.
Firstly, the autocomplete UI has been reworked - the basic interaction now works as most applications do (type to narrow down the results, arrow keys + enter interact with the dialog), but it now uses similar fuzzy matching logic to the quick panel, so it'll happily match using abbreviations, skip missing characters, etc.
Ctrl+P and Ctrl+Shift+O have been merged into a single list of files to match, which is now bound to Ctrl+P. The scoring function has also received some improvements, so the file you're after is more like to be the first match - I'm very happy with how well it's working.
If you're still using Sublime Text over Sublime Text X, I'd be happy if you could let me know what is holding you back from moving. Personally, while I'm using Sublime Text X almost exclusively now, the biggest thing missing is find in files.