7rider did an end-to-end ride of the Parkway within the last year if I recall. You might use the search function to find he posts/threads about it. I've had several friends ride all or part of it. All have said it was pretty challenging. You're a relatively new rider, right? If so, I tend to think a Sept/Oct timeframe for 2012 would be somewhat more realistic. Unless you can ride hills all winter, doing it in the spring--regardless of how experienced you otherwise are--would be tough. Plus, you'd encounter a lot more wet weather.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher