I just committed a new bundle for review, SecondLife LSL http://macromates.com/svn/Bundles/trunk/Review/Bundles/SecondLife%20LSL.tmbu...
I forget why I never shared it before. Seems pretty done. There's code completion and everything. There's even contextual help set to ⌃h (ctrl-h) which searches the lsl wiki.
I think I used someone else's language bundle to start out with and then modified it, but I can't remember at this point, so I'll take all the credit ;)
It's been a long while since I've played with LSL. But I don't think the language has changed much in the meantime.
Let me know if you have any issues.
—Thomas Aylott – subtleGradient—