I'm setting up my notebook from scratch, and I'm hoping some more experienced folks can give their recommendations in terms of how much HD space to allot, VM vs Dual Boot, etc. I have an ASUS G73S w/ 8G Ram and 500G Hardrive (2 x 250G).

My primary uses will be:

-- First and foremost - Web/Android development (ubuntu ). Most TIME will be spent here.
-- Image & movie editing with Adobe Photoshop and Premier Pro (windows 7). Most HD space will be required here.
-- Routine Internet Stuff

So, to test IE and for various editing, I need to be able to quickly bounce between Windows & Ubuntu. So VirtualBox (instead of dual booting) seemed to be a logical idea, but I'm reluctant because when I used it a couple years ago there was considerable latency. Not good for Image/Movie editing. But dual booting makes Web Development a nightmare, having to reboot all the time just to test IE.

I'm hoping I'm just not up with the latest and greatest of what's out there, and there's an obvious solution someone can suggest. Thanks in advance

Go for dual-booting. It's the only way to get the full potential of both operating systems, and hardware.

Not exactly a suggestion to a layout but if the "stuff" you'd like to test on IE are static, e.g. no requirements for clicking and stuff (in other words you'd like to see the design), you could use http://netrenderer.com/ to figure out if IE displays things correctly.
You could try Photoshop and Premiere under wine, the reviews in the appdb are quite old, so perhaps wine 1.5.5 is capable of running them. My 2 cents.
P.S. Windows 7 runs quite smooth under Virtualbox at least for me, so you could give the latest version a try.