In reality, Samsung and HP are the only two big name tablets running Honeycomb set to hit the market this year. If both are flops (like the Xoom), it's highly doubtful people will continue to maintain interest.
Didn't HP basically say "Ew, Android, go away" and bought Palm for WebOS?
I just don't see what's special about the Samsung tablet. It's going to be a sleeker, thinner version of the Moto Xoom with a better screen but running the same CPU and the same OS albeit potentially a much faster GPU, depending on whether they go with the Tegra2 or the Exynos. (Not that it really matters in any case. There's very little software that take advantage of extra 3D power in Honeycomb)
Essentially most manufacturers are constrained what can be done by ARM for the CPU speed so there will not be that much of a difference between tablets in the same generation in terms of raw performance other than the GPU but even that should be equalized. Currently it's all about the industrial design and the OS/software and in those two areas, Apple is arguably holding a huge advantage with Honeycomb not making much of a progress yet.
I'm personally much more interested in the HP tablet. I finally got to try the Xoom and the Playbook and both just felt rough. The Playbook was especially disappointing because the UI actually looked very nice and tastefully done, which I couldn't say about Honeycomb. Random slowness was abundant and the rampant checkerboarding in Playbook's browser was very surprising. Not to mention the general weird feeling of touch response - it's speedy but somehow feels out of sync.
(And yes I rebooted the devices, killed all the tasks, made sure the upgrade was up-to-date, and tried multiple devices to be sure it wasn't just one demo device.)