According to a recent post on the Microsoft Update Product Team Blog we can expect a new and improved Windows Update as early as the end of this month. It looks like they'll be rolling out the change gradually though.
So what are we doing this time? Well, this particular update won’t really change the way the client looks or feels to you, but you may notice some improvements in the length of time it takes Windows Update to scan for updates and how quickly you’ll receive signature updates. For example, in this update, we’ve invested heavily in reducing the amount of time it takes the Windows Update agent to scan to see if new updates are available. In this case, we’ve seen some instances of the scan times on some machines decreasing almost 20 percent.
That's a 5 year old e-mail they're quoting there. While interesting, I'm pretty sure that there have been changes to Windows Update since then. It actually works quite well today compared to the era referenced in that blog.