Catch it while its live! Check out the MSN Search Preview up probably for the night. This time around appears to be some slight changes, and some very fresh results. From some testing I have done in the last 30 minutes, we found that post made this past Friday are already in the index. Screen shot below in case you missed the preview. Some things of note in this preview. Web site with keywords in the domain seem to help, but in comparison to the last preview as reported on SEW forums, not as much. The cache is still fresh from what I can see, but not as fast as it can pick up pages. An example search for "web development" or some of my own terms returns up to 221,313,454 results. Pretty impressive.
Check out the 3rd MSN Search Preview
Update: Check out Nacho's initial observations at SEW Forums.