I don't know if you read to the end of the thread you linked before,
but I finally did create and post an very comprehensive XSLT 1.1
snippet collection.
http://www.ditchnet.org/wp/2006/12/19/textmate-changed-my-life/

Yep, i read to the end of the thread and view all links (and sub-links). And i download and view your snippets.
But you can compare -- ours snippets based on different ideas:
yours example -- "choose" for xsl:choose (too long abbreviations for tab-triggers) with long travel by tab-stops for make what i need, and after that "when" fon one more xsl:when.
my example -- short acronyms, based on snippet content: "cwt" for Choose-When-Test, "cwto" for Choose-When-Test-Otherwise and just "wt" and "o" for When-Test and Otherwise. In my opinion and practic it's shorty in process.
Next, my bundle has language definition for xsl-scopes and so scope-based context-dependent snippets and completions.

More importantly, I've developed an XSLT/XQuery TextMate Plugin you
might like. It allows you to edit your stylesheet or query in a
TextMate document and then execute it against any source document
(local or remote) from a floating palette. Also supported are
external/global variables, multiple views of the results, and a handy
error console.
http://www.ditchnet.org/texslmate/