We Got Served is reporting that HP has upgraded its interesting-looking ProLiant MicroServer series with a new model that sports Windows Small Business Server 2011 Essentials. (I was previously considering buying one of these things for Windows Home Server 2011, coincidentally. Or as others would say, "ironically.")
The HP ProLiant MicroServer series starts at $329, and I'd still consider that one for a basic WHS 2011 set up. In fact, what the heck. I'm ordering one right now, the mid-level model for $349, or about $390 after taxes and shipping. (I'm not sure yet if I'll use this for WHS or SBSE, but if it works out, perhaps I'll get another and use it for both.)
Note: the Windows Home Server Blog reported recently that a similar machine, from Acer and pre-installed with WHS 2011, will be available soon as well. If you're looking for a new WHS box, you might want to wait on that. (Here's a link to the specs in PDF format.)