Actually, let me respond here as well, so that it's a common-enough resource.
I've not really found any site that's too much an equivalent of this one in terms of the .NET space. (I've been out of that field for about a year now, since I'm back working for a pure-Java company.) The one site that I found in terms of certification that's at least semi-useful was techexams.net, but I'd almost suggest more just looking in the various Microsoft usenet groups.
Theodore Jonathan Casser
SCJP/SCSNI/SCBCD/SCWCD/SCDJWS/SCMAD/SCEA/MCTS/MCPD... and so many more letters than you can shake a stick at!