Hi,
I got a couple of suggestions.
First of all, open URL: I'm used to clicking on a URL in a text and go to that URL in a webbrowser. In Mac OS 9, there was an extension that allowed to do that by command-clicking on any URL. In Mac OS X virtually all text editors or text viewers, if you right-click on a URL, you get a menu which (among others) says "Open URL". Try BBEdit, SubEthaEdit, Stickies, or TextEdit. They all have this feature. Except for TextMate. Perhaps I can create it using "Filter Through Command...", but that's clumsy. I suggest to add this feature like in all other editors.
Second, Diff's: Well, this has been discussed on the list before. The diff function in TextMate is not really useful. Actually, Compare Texts is still the only thing I use BBEdit for. Even though Apple's FileMerge does a better job of showing the diff's (much better then either BBEdit or TextMate), BBEdit most definately has the best integration of viewing AND editing diffs, as well as ignoring line endings and white space (TextMate diff can't handle anything but unix line endings). This is very high on my wish-list for TextMate.
Last, draffing URL's: Dragging. I struggled long to understand "DragCommands" (there is not useful mention of them in the help or on the wiki). I would love to be able to make a DragCommand that allows me to drag a URL to a HTML text file, and that the drag then automatically inserted a <a href="$URL">$name</a>, preferable with the previous selection as the $name. However, it seems that now, DragCommands only work on files, not on other drags like URL's and images.
Oh, sorry if I sound critical. I love TextMate. I really adore the UTF-8 support (actually that was the single most important reason for me to make the switch to TextMate as my default editor). Keep up the good work!
Regards, Freek Dijkstra