^Those are looking good Jeff. My feeling is that if you can use a longer lens to shoot architecture, because their aren't obstructions, then the building will often have a more pleasing appearance in the photograph. Those church buildings look very nice at 45mm. I'd like to see Canon make a 35mm TS-E, although I can nearly approximate it with my 24mm and a 1.4 extender.
How are you liking the sharpness and color rendering of this lens as compared to the 17? Since I have the 17 and 24 II already, there's a bit of a "collect 'em all" thought lurking in my brain, but the 45 and 90 seem to render quite differently than the 17 and 24.
The sharpness is very close in my opinion, but the color and contrast is a tiny bit lower then their L series cousins. But, that can usually be fixed in Photoshop with a bit of careful adjustment.
I doubt they'd ever come out with a 35mm TS, though. Probably not enough of a customer base to justify it. Plus, like you said, the 24 along with a 1.4 extender gets you there if needed. Though I don't know if it would mount safely?