Turns out I didn't pay enough for my house for this to make a difference.[1] If you're already over the standard deduction without the house you can get back a ridiculously high percentage of your housing cost through tax breaks. If you're already living frugally, though, it might not matter. Except that you may be building equity, of course.
As deSitter suggested, the only time you don't want to buy is when real-estate prices are falling faster than you would be paying off, which in the first couple of years of a mortgage is barely at all.
[1] We both came in to the marriage with school loans and other debt, and planned to be debt free in time to move after five years. Depending on what the market looks like come spring, we just might make it.