This is now appearing on the BrowserLab website:

Notice: On April 30 2010, the limited free preview of Adobe BrowserLab will conclude. BrowserLab will become a part of Adobe CS Live, a set of online services for creative professionals.

To continue using BrowserLab, you’ll be asked to sign up for CS Live with your existing Adobe ID. This will only happen the first time you access BrowserLab on or after April 30, 2010. If you sign up by April 30, 2010, you will receive one year of complimentary access to all CS Live services.

BrowserLab will still be accessible from http://browserlab.adobe.com. For questions about CS Live, please visit our FAQ. Thank you being a part of the BrowserLab free preview and we look forward to your continued participation.
The CS Live FAQ is here: https://www.adobe.com/products/creat...e/faq/?tree1=0

Pricing

Here's the relavent info:

What does CS Live cost?

When you sign up for CS Live before April 30, 2011, you can take advantage of 12 months of complimentary access. By the end of your complimentary period, Adobe may offer for-purchase subscriptions. Final pricing of for-purchase subscriptions is to be determined, but is currently estimated at US$19.99–$29.99 per month or US$199–$299 per year.
Hmmm, you also get a 12-month subscription with the purchase of the CS5 Suite. So if you purchase or upgrade now, you may want to consider getting a complimentary subscription under a different Adobe account come 2011 to maximize your free access to Adobe Live (if it's doable).