I like text figures a lot. It definitely gives a classy feel to any text.
In my CSS, I ask for "Hoefler Text" (for Mac), Georgia (for Windows) and… nothing for Linux.
So I ask for a DejaVu variant with text figures or, better yet, text figures as allographs of usual numbers. Mac OS X allows choosing the particular allograph I want, but I am not sure if something in the css allows forcing an allograph in particular (context is downloadable fonts, of course).
I wholeheartedly agree with this suggestion. If you don't want to make them the default figures, they could be implemented as an optional variant through the onum feature of OpenType. They're very classy and pretty, essential for qualitative typography.