Each page is now a wiki page :-)
For very large repositories with SharePoint 2010 the built in support for SQL Server Remote Blob Storage is a huge win for those implementing archives
Pages now have built-in content areas that are literally click and type. Beautiful experience. A "standard" wiki (wiki library) hasn't changed much in 2010. You can create a wiki library the same way as you could in 2007.
I hope we answered it for you--standard wiki library same as 2007 basically, but all "Pages" are now basically templates with Wiki-like content areas, and you can use some limited wiki syntax. There's also a great "little thing means a lot" in Wiki's--you can pull in information from lists and libraries, and there is a "predictive builder" that helps you figure out exactly the path you need to enter to do that.
One of the most exciting TOTALLY new features of SP2010 is the Managed Metadata Service, which allows an enterprise to manage "terms and keywords" that can be used as tags throughout the enterprise. You can manage terms as tightly (taxonomy) or loosely (folksonomy) as you want, and you can move at a reasonable and practical pace (i.e. AGILE) towards a more managed taxonomy. PLUS the mms allows you to publish content types so a single content type definition can be used across site collections, web apps, and even farms. That’s a BIG deal because it was a major pain point in 2007 that kept organizations from wanting to use multiple site collections. The two (terms and content types) are the foundation for supporting your information architecture.
Spencer: There are just too many cool new features in SharePoint 2010.... Take the Office Web Applications for example; rich, accessible, editing and viewing of your favorite office file formats, all directly from the comfort of your web browser.
<i>This question was answered by Spencer Harbar, Enterprise Architect at Microsoft and Dan Holme, Consultant and Trainer, Intellium.</i>