For general computing purpose (e.g. HTPC + bittorrent + samba), there are always something missing with these small ARM computers. I am holding on to my AMD E-350, especially with the rapid improvement in the radeon driver lately.
Gigabyte Brix with AMD Kabini is going to be interesting, and possibly very competitive in pricing without sacrificing performance:
Wyse and HP will probably refresh their thin client product lines with the new AMD APUs as well. Re-purposing those if you can get them second-hand can be quite cheap and get you the hardware you want (HP has standard BIOS, Wyse boots SUSE so should work with some fiddling).
As a side note, I have had a lot of fun with thin clients in the past few years due to a variety of interesting x86 architectures (AMD Geode, Transmeta Efficeon, VIA Nano) each with its own little quirks and features (accelerating torrent hash checking and peer handshaking with hardware sha-1 crypto engine and montgomery multiplier on VIA cpu was probably my silliest project).
What I'm looking for is a board with a reasonably fast CPU (preferably dual core), SATA and a a PCI-E or USB3 port for a fast 802.11n/ac wifi adapter. PogoPlug v4 is almost there, but the CPU is too slow to sustain more than ~40MB/s of I/O.
