I'm a fan of ergo keyboards and actually really like the Microsoft Natural 4000. I've got one at home and one at work. The benefits of having the SAME keyboard at both places are pretty significant--probably more so than the keyboard itself--as I don't have to get readjusted to the "qwerks" of each keyboard type at different locations. I pick these up for around $20 USD when they go on sale. I don't know that this new one offers much over a smaller size, which doesn't do anything for me. In fact, the padded palm rests of the 4000 are a major plus in my book.
As for wired, well, that too bothers me not in the slightest. I don't much move my keyboard. The mouse is a much better experience when wireless, as the constant movement tends to make the wire a bit cumbersome. There, I love the Logitech mice with the free-scrolling wheels for zipping through long documents. Yeah, I have NO brand loyalty whatsoever.