Maybe they are being too ambitious? Why not just release the motherboards and forget about the complete package.
Well, they're using a stock case that's been available for a couple of years already, along with other stock components you can order from just about any PC components retailer. The "complete package" isn't the part that would be holding them up.
The board itself is being built by a reputable company and appears to be pretty much finished, except now it's Revision 2.1 when it was Revision 2.0 just a couple of months ago so not sure how far that delayed things. A-eon has announced twice so far that they're going into production (March 18 and again June 7) so it seems like the board is ready to roll.
The big delay seems to be the software.