I am using 1280x1024 resolution, but to think of a site in long-term rather than what people are using now but what everyone will eventually be using, fixed pixels are not beneficial to a site. You can use 100%, 110%, etc. for sizes and let a person's monitor make the decision on the size. This would also mean you couldn't have fixed width tables as well. I would say that, if this isn't viable with your layout, then ems would at least be partially better. 11px is pretty small on my size resolution, and I know people using 1600 resolution, too.