Most people will be getting this camera for it being a camera, not a camcorder (it doesn't have af while filming either - so only really is an option for film enthusiasts). Filming in 720p is high res stuff and will take up lots of space, and while the feature is great, it will be limited by the memory card technology itself.

I'd say 10 minutes of filming normal quality and 5 mins in 720p - on current card technologies.