It looks increasingly unlikely that Honeycomb will appear on the NVIDIA Harmony platform, which includes the Advent Vega.
However, that doesn’t mean the community couldn’t make a custom rom, but it’ll take a lot of work. Google aren’t releasing the Honeycomb source (instead we’ll have to wait for Ice Cream), additionally the community will need to integrate the drivers manually from NVIDIA.
While I’m sure we’ll see Honeycomb on the platform, I doubt it’ll ever be a nice slick implementation that you would get from an OEM-based rom. To be frank, if you want Honeycomb, best start saving the pennies for one of the latest generation of Android tablets. The Asus Transformer looks especially tasty. Personally I’m waiting for the quad core Tegra and Ice Cream, Froyo is enough for me for the moment.