Yeah, I doubt we'll see this. Like KDawg said, WP7 apps are designed to fit in those resolutions, be it 800x480 ad/or 480x800. Controls like Panorama and Pivot are for a phone UI. The layout is for a phone...the design, has a phone in mind.
This is the reason I was disappointed the "native" UI widgets and toolkit present in WP7 were entirely re-implemented in Silverlight: by having two different implementations of the same concept it means twice the effort is involved in doing "mind-shifting" work such as allowing WP7 apps to work on a PC, such as (for example) "expanding" the panorama view so all tiles are simultaneously visible. I believe this is the sort of thing Apple might do if they made a platform like this (using their ObjC-based frames throughout, no doubt) but thanks for the Silverlight lock-in (or rather, lock-out from system-provided services) you'll see that things really are constrained when it comes to ensuring applications can take full advantage of future runtime environments.