Hi,
No, I haven't yet made the jump to Cp7 (as a fairly recent purchaser of the full elearning suite 6 (including Cp6), I'm still pondering the jump to a Cp7 subscription, especially since there is no Cp7 pricing discount for suite owners, and there's been no clear announcement (that I've seen) as to whether there will be a future for EL suite that includes Cp7 --- I'd guess there are many like me who are on the fence until Adobe addresses this suite question).
But, I see no reason why html5-based files would not render as expected given the iframe approach the web object uses, assuming your browser supports the html5 features used. I would expect that the same would be true for the Web Page widget that can be purchased for Cp6. There is a need in any case, I think, to have the w-mode setting in the flash object html tag to be set correctly for these iframe-based schemes to render properly on top of the captivate SWF --- I would assume that's addressed in the way the html page is published by Cp7.
Doug