I don't think it's about security either, but I'm just fine without Flash.
>I think so this's not about security. Microsoft wants hold WP7's control and and it's way unsupport flash. Iphone doesn't support flash for this reason too. They have an appstore. You develop application and put it their's appstore. So I think MS nor Apple won't support flash.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer