Hey everyone, I apologize for the delay in getting back to some of your questions (yesterday was a crazy day!), and I want to address some of them here. We’ll have to ask for your patience on a lot of the questions, but please rest assured that we’ll be sharing a lot more details soon!
By the way, I just have to say this ahead of time: the entire Webflow team is incredibly excited about the response to our announcement so far, and we’re working really hard to get the beta in your hands!
Since there are quite a few threads with comments, I’ll try to pull stuff together here…
@Veloce While the development of this has been a big technical undertaking, it in no way affects our commitment to creating the world’s best web design software possible, whether you need a CMS for your sites or not. We are laying the technical groundwork for custom grids (including mobile-first!), more widgets, more CSS control, etc - so it’s just a matter of time.
Getting everything seamlessly integrated into the current platform has indeed been the biggest technical (and UX/design) challenge. We had the option of integration something off-the-shelf (e.g. Wordpress), but in order to do it right, we had to start from the ground up.
It is indeed something you can turn on as an option, and by no means changes anything existing about the existing Webflow software. (In fact, a lot of the enhancements we had to make directly benefit the existing workflow for creating static sites.)
@Golden28 Nothing about the current Webflow designer will change. Current sites will not be changed in any way. While it’s a huge feature (our biggest yet, by a long shot), it will be something you can optionally take advantage of, like Interactions and Symbols.
@expatabroad We started collecting a list of everyone interested in joining the beta yesterday, and our intention is to slowly start rolling out invites as we fix the last remaining breaking bugs and issues. It’s hard to give exact timelines, but we’re working as fast as possible!
@Arthur What kind of access do you want your clients to get? My guess is that you don’t want the client to want to worry about the template, only the content 
It will not change how you build non-data driven sites, and there are quite a few enhancements that will make it even better (hint hint: rich text fields!). And the main reason we started building this (and started the company in the first place) is to remove limitations and restrictions placed on designers, so our mission is to get rid of them. Both @thesergie and I used to run Webflow as a web development shop, and Joomla + Mambo + WordPress were the banes of our existence, so please know we want the same things
@bartekkustra Well if you ask…
Let’s bump that to 100% soon! 
That would be @nate 
The fine folks at http://www.giantant.ca/ - check out their other videos!
The first version will definitely be a Beta, so I would be cautious in giving clients any big expectations before you have a chance to really test things out.
It’s very hard for us to give exact dates, but we are working day and night to get the software ready to send the first batch of (private) beta invites in the next few weeks.
Thanks again for all the questions and excitement around this! We’re working on an FAQ to address the most common questions, so more answers coming soon