Thank you for the tips! I don't plan on using the Surface as my primary machine. It's a toy, but a fairly capable one, and thought I'd share my experience, since others seemed interested. :)

I have a desktop machine both at home and work that are more than capable machines. As well as a fairly capable laptop. While I don't have the experience with Poser, I do have experience with other 3d modeling software. 3ds max and zbrush are part of my stable of software. Though rendering can be a chore in 3ds max as well.

Again, just sharing my experience with the Surface Pro. It wouldn't be the choice of an artist, I'm sure, but I'm still impressed with what it can do. After effects, premiere and photoshop as well. Though stylus pressure sensitivity in Photoshop isn't currently working (Adobe has mentioned an update to resolve the problem).

I've been running it without any problems. Navigating, manipulating and such works well. I'd say the worst problem is some of the buttons/controls can be difficult to tap, but when using the stylus that came with it the tablet, it's not really an issue.

Rendering takes time, of course, but I don't have much of a comparison for how long renders typically take in Poser, as I'm new to it. But, after installing Anastasia, and rendering one of the setups that is included with it (model, pose, lights, backdrop), it renders in probably ~2 minutes.

The tablet hasn't had problems with much of anything I've thrown at it. I've loaded Mass Effect 2, Bulletstorm, and a couple other games, and it runs them well. Typically at 720p, with around medium settings. Obviously not a gaming PC, but it definitely holds it's own.

If you'd like to know anything else, I'd be happy to help, as you've all been helpful to me.

Yup! It's a Surface Pro. Which is capable of running legacy (Windows 7  desktop software) http://www.microsoft.com/Surface/en-US/surface-with-windows-8-pro/home

Admittedly a bit expensive for a tablet, but you pay for performance, right? :)

I apologize for my delayed response, and sincerely appreciate the great community here for their responses.

I feel like a fool for not noticing the "install from zip" option earlier. Using that method worked for me. Previously I had installed the files in my "program files/smith micro/poser pro 2012/runtime" directory, which did not work.  

For future reference for anyone else who stumbles upon this thread, I'm running Windows 8 Pro (64 bit). It's actually on a Microsoft Surface Pro. 

Thanks again for all those who responded with the very helpful information.