It's somewhat draining hearing so many web 2.0 pitches which amount to 'We're going to work exactly like the tool you're used to, but without synchronous server round-trips. Isn't that great?!?' No -- that's not great. It reminds of all the boom-startups who thought moving mail-order to the web was revolutionary ... after 12 months or so it's just too obvious to really be intriguing.
So I didn't have high hopes when I met a couple of folks working at one of my office-condo neighbors, and found out that their company (Kyube) is doing a web 2.0 CMS called SimplifyCMS. But they demo'd it for me, and I liked it a lot.
With Simplify, you create an account, supply a URL, and they spider your site and serve it back to you from their WYSIWYG-enabled site. It auto-discovers repeated content blocks, and has specific support for FrontPage and Dreamweaver tags. That's so smart.
They also autodiscover blocks of content within a page, and allow you to set permissions on who can modify the content using default roles (Admin/Editor/etc).
Provide an ftp account, u/p, and folder, and they'll publish the site back out to it. They archive your site and provide versioning, all the stuff you'd expect.
I'm passingly familiar with CMS-goliath Interwoven, and I think there's a fair amount of functional overlap, but Kyube has stripped out a lot of the hard stuff you need for traditional backoffice CMS integration and instead are relying on AJAX/client-SOA/mashups. They do offer onsite deployment if you want to make it work/look like traditional CMS's, and I was very impressed with how well the product scales both up and down given the deployment options. I think they might actually compete well with low-end CMS's like FogCreek's CityDesk as well as higher-end offerings like Interwoven. That is a feat.
There are a couple more novel ideas that they mentioned. They have a variety of pricing plans, including per-push (when you refresh a live site). This is awesome, because my experience has been that maintaining web content is a huge chore for clients, and pricing it in line with the frequency of updates works very well. It provides huge financial scalability compared to the more involved competitors. It will very likely be much cheaper to steer clients towards something like simplicity than even taking the time to implement and maintain a free Mambo/Typo3/Plone/etc.
For more dynamic sites, they have some canned base class functionality for ASP's/Service Providers that need the basics of user registration and billing. This is similar to what Ning provides to social-network-app developers, but I think Kyube's vision has much more marketability. I didn't dig too deep here, but I think their offering is pretty compelling either way.
And finally, they've got a novel idea for allowing 3-party developers to publish their own AJAX widgets et al ( like ASP.NET or CFML ) and charge for them on a subscription/per-use etc basis. This is very similar to Salesforce's trendy AppExchange, but again with a much bigger market potential. Kyube'll take care of all of the sordid bookeeping details that your typical masher-upper is not interested in doing. There is naturally an open source element to all of this (they'll kickstart their exchange by open sourcing some of their internal components), just to make sure their web 2.0 buzzword bingo card has no spot left uncovered.
Oh yeah, did I mention they're in beta? BINGO!