One of the most compelling features of Microsoft Access 2010 is its ability to post an Access database on a SharePoint 2010 site and have it run over the web. Some people hear this and think they'll be able to take their existing Access application, all its VBA code, etc., and make it web enabled. Unfortunately, that's not the case. What you can expose to the web is forms and reports that don't use VBA code. That's obviously a severe limitation, but on the plus side, what is possible is the deployment of databases that have automation through Access macros. The macros are automatically converted to JavaScript code. That's pretty cool.
An Access database that's hosted in this way can still be used locally on a desktop that has Access 2010 installed with all the rich functionality of Access, VBA, etc. The data is then hosted in SharePoint which exposes it to the web. So while it's not making it possible to publish an entire Access application with VBA to the web, at least a portion of it may be exposed with little to no additional effort. Letting people browse data, filter, and generate simple reports is all available and possible by non-programmers. It's a big step forward for the Access community.