If so how would we download them?
That's a good question. Yes the beta will definitely be receiving updates, as per the roadmap. Whilst we haven't figured out a schedule yet, new builds will be available to beta backers via threads on this forum. In due course the process will get a lot more streamlined (eg auto updates via steam) - again, we're trying to figure this out together with you guys, so I'm sure we'll settle into something that works well for everyone soon.
Also, i should mention if you're a beta backer and you can't see the beta build threads (there is one already) then please PM with the email you used to purchase your Beta Program membership and I'll sort it out manually.