I replicated your test, I received a similarly shaped graph, but my CPU usage hit a plateau around 65%. I have the same 2.4ghz P4, but with only 512 RDRAM. I'm not sure it would spike so much with more programs open, as the others weren't taking up many CPU cycles before you opened the site. My processes count is half yours. Perhaps getting the newest version of flash would help, but I have no idea...
I complained about that as soon as the new site came up - it's the top graphic on the page & only because it is two layers moving with alpha channel - takes a lot for flash to figure that out. It's pretty and everything, but there should an option to stop it.
I sometimes browse at the office when my computer crunches numbers - I don't like having to make sure that the Lotus site isn't open while that's going on in order for the majority of the workload to go towards my app and not some webpage.
yet another complaint I have about the LCU's website.