Thanks for the advice. I believe I know my limits and will not go beyond them. That's not to say that I'll challenge myself on the way up.
From talking to a guy at REI tonight, he made it seam as if the hike isn't terribly difficult. Crampons might be needed but aren't absolutely required. He did advise, though, to check with the ranger station for the most up-to-date weather and trail conditions. I picked up Paul Richins book on Mt Whitney while I was there.
Unfortunately, the only comparison I have is Half Dome in the summer. It didn't seem hard at all and was quite easy in some parts. While I was tired after the day was done, there was an accomplishment in hiking up and back in a day. I hope to get that feeling again at Mt Whitney.