I think that
http://www.alistapart.com/index.html has a few goos points about 4.x browsers (and some brain-dead later ones) and sites look/usability.
There should not be a general problem having usable design, that standard compliant. It may not necessarily look the same as it is now (i.e. tripple-column with a big header on top may be a bit tricky to tailor), but maybe that's a good thing?
Also, another nice redesign article was here: http://www.webreference.com/authoring/style/sheets/layout/advanced/
