I'm very excited to see positive reviews for Keep on the Shadowfell hitting the net. Here's one from gamingsteve.com. If you're interested in trying out 4th Edition D&D before the full rules are published next month, why not try this module? Not only does it provide quick start rules for the game, it is the first in a series of loosely connected modules.
Though not required to have played any previous module to enjoy a later adventure, discerning DMs will have the opportunity to pick up storylines in later modules that first debuted in Keep on the Shadowfell.
An excerpt from gamingsteve's review:
The module comes with a comprehensive set of quick-start rules for both the players as well as the DM (the DM rules are more comprehensive and cover more topics, as you would expect with a ruleset for DMs). If you are familiar with D&D and the rules to 3.5, then picking up 4th Edition should be a piece of cake.