After much fruitful discussion and evolution, this proposal is now a series of "Bitcoin Improvement Proposals" -- see BIP 11, 12 and 13: https://en.bitcoin.it/wiki/Bitcoin_Improvement_Proposals
Sincere thanks to everybody who contributed improvements, ideas and code.
@gavinandresen - I feel that there is a reluctance to accept substantial contributions from the community. As @maaku I am also concerned about community trust and I think the success of bitcoin project depends on that and good communication. A decision was made even though the balance of arguments seemed in favor of the generalized solution.
As to code complexity, the IsStandard part of pull #319 is very simple - https://github.com/bitcoin/bitcoin/pull/319/files - wallet.cpp line 1125 to 1179. The only other part is a refactoring of Solver in script.cpp that is generally useful. Extending this to multiple OR clauses will be only a few more lines of code.