Sam440Flex was announced today. Board with 800Mhz CPU for 399EUR. So already cheaper than what Keropi previously listed.
This looks really interesting to me. Especially as you can plug CatWeasel PCI card into motherboard. If someone were to provide working drivers for CatWeasel in OS4.1, you might be able to run Amiga floppies in OS4.1! That and better E-UAE emulation (running Amiga app automatically spawns emulated instance), would make Sam440/OS4.1 a compelling replacement for aging Amigas.