Let me start off by saying that I think this theme looks fantastic. I think I may have found an issue with IE8 though. It seems like this theme causes the browser to eat memory in large chunks.
base browser memory = 20,756 kb on browser open
browser memory after loading the "neptune-components" example with the neptune theme parameter: 192,746 kb
view each example once by clicking on the tree node for each example and the browser memory is now at:
I have repeated this several times in a row. Let me know if I can provide any more details.
Win 7 x64
browser mode: IE8
Document Mode: IE8 Standards