Interesting issue about Honeycomb raised on the CNet UK podcast a couple of weeks ago: sure, 3.0 is built especially for tabs, but the most fundamental thing it affects are apps / app icons and widgets. Since tabs are bigger it's likely that you'll be doing more things direct online (via browser) rather than via app, which is essentially a series of programmes that rely on on-line content anyway. So, actually, beyond the under-the-bonnet improvements, Honeycomb really isn't that necessary for an enjoyable tab useage experience.
Not sure if t his is true or not, but it's an interesting point.