Are you sure that isnt a problem with your ethernet drivers that are written for Vista? I have not had a problem at all with my net since i start using Vista Beta 1 back in July of 05.
I think the drivers or your router would be more likely than Vista.
As for the Beta..we dont know what is included yet. They have not said. But i am guessing that there are 2 things included.
1. All the patches and security updates to date.
2. The rewritten search function. This was brought on by the Google thing where they wanted to be added to their lawsuit against M$ from 4 years ago. They claim that with Vista new search function they eliminate competition since the Google Desktop app no longer works correctly within Vista cause of the way it is now incorporated.
Other than that...we will jsut have to wait and see. I have not seen any invites to it or anything along that line on Connect yet. Nor have i heard anything in the newsgroups. Nor have i heard anything from the inside sources that i have.