Will a Keynote with a video in it export to PowerPoint properly

I don’t know if you can do that with the presentation itself (a Keynote document being “played”) but if you can make a movie (hint: in Keynote you can record your presentation) of the slides (so they become a Quicktime movie and not a set of slideshows), you can later use any movie edition software (not iMovie) to create the desired effect.

An expensive but very powerful one is BoinxTV. It’s really powerful and easy to use, but doesn’t support using a keynote as a source, only different types of images, sound and video.

Of course Final Cut (pro and express) would be able to do that too.

As good as these solutions may seem, they are not real time, in a sense where you can be giving the presentation while you receive a live video feed of you being recorded and dynamically decide to “zoom” into the slide. That is much more complex.

Now if you can edit and post-produce the slides and you giving the presentation, those tools will probably suite you.

Unfortunately, Keynote and Powerpoint do not talk to each other all that well. A lot of formatting issues have been known to occur.

If you're wanting to view/edit/present the presentation on your iPad, I would suggest using Keynote on your Mac and Keynote on your iPad. If you're wanting to stay as compatible with a Windows environment as possible, I would suggest using QuickOffice HD on the iPad and Microsoft Office for Mac 2011.

Hope this helps.