Microsoft has recently went public with their Architect certification program  - While (naturally) they expect knowledge of the Microsoft platform ("about a quarter of the emphasis" to quote the site), it also has a lot of of emphasis on architect competencies and general know-how. Way to go MS :)

On the Java side of the fence there are already architect certification programs e.g. Sun's or BEA's.

There are also two (that I know of) non-vendor specific certifications - one from the Open Group (they also brought us TOGAF - which is worth its own discussion) and the other from the Software Engineering Institute (SEI @ Carnegie Mellon university)

I 'd be happy to learn of any other architect's certification programs if you know them