Agreed
WM6.5 and 6.6 will stay the primary focus for businesses until the next build of SCMDM ships with WP7 support and things like an IRM client are released for it.
The fact that WP7 isn't 100% corporate ready at launch doesn't mean that all companies running WM handsets have to toss them out and buy Blackberries, it just means that they shouldn't make the jump to WP7 on day one. Think of it as a staggered release instead:
Late 2010 - release WP7 for consumers and small-mid sized businesses who don't use IRM, SCMDM or deploy custom apps
Early-mid 2010 - WP7 launched with support tools for large business/corporate.
I honestly think it's a sensible enough path for Microsoft to take. Consumers and small businesses are early adopters, so you get the 1.0 release of your product ready for them. Corporates are always going to hold off for at least six months, so that gives you some lead time to build the supporting products and large-scale management tools that those corporates will need.