Linksys is trying to ratchet their entire product line downward in order to meet competitive pice points. The WRT54G is pretty much the lowest end box now, and that should give you a clue that it's not going to be interesting to a serious user. In order to get that box down to the price point it needs to be at (about $30 street), they had to reduce the cost of goods. A quick bit of research between Linksysinfo.org and Mouser's catalog says that in small quantities they could save about $5 COGS - in the volume Linksys does they could probably get massive discounts to start off with so we're probably really talking about $2.50 COGS savings. But that translates to a $25 MSRP savings. Which is pretty much the difference between the previous $50 price point and the new $30 price point. So the math says they had to cut, IMO.
All that said, it's a downright dishonest practice to build up a good reputation for a product (the WRT54G) and then slip a silent revision into the channel that is substantially a different product (completely different software), and has a substantially different level of quality. This should serve as a reminder to all that brand loyalty is foolish these days, because so many manufacturers will happily screw over their customers for a buck.