(I can call you Bret, right?)
In an ideal IT world (run by either Bret or Craig), developers would know T-SQL, and DBAs would know .Net.
But in practice, I haven't usually found thing works out quite so ideally. Most developers in the MS shops I've seen know .Net, of course, and also a fair amount of T-SQL. But working with the CLR is just beyond what many DBAs are accustomed to doing.
Again, that's not to say they shouldn't learn - but often, the demands and requirements of the DBA's job mitigate against it. And some DBAs really want to avoid programming altogether - due to a lack of interest, a lack of aptitude, or both. (They had their reasons for becoming DBAs, after all, and not developers.)
Re SQL Server's 'shelf life': while all good things must eventually come to an end, as you pointed out, T-SQL is apparently still far from its 'sell-by date'. The same cannot be said (at least at this time) with the same surety, of .Net. This was one of my reasons for suggesting a T-SQL-based solution might be preferable to a .Net one.
Regardless, I think you've crafted some truly wonderful code, and I'm sure any number of people will be taking advantage of it. Thanks.