In InfoPath 2010 and SharePoint 2010, we can now customize all list forms within InfoPath. This is a huge improvement in SP2010 and something I plan to take advantage of often. One other major feature is that we can build External Lists based off data in external data sources, and then we can STILL modify that list's forms with InfoPath. You can't beat that. Here is my write-up explaining that piece:
InfoPath 2010 – Designing External List Forms
From that blog post, I also have two others that explain how the External List was created, if you're interested.
One thing I've found from my testing is that despite these new, awesome features in SharePoint 2010, Qdabra still has a better tool for InfoPath forms to interact with external SQL data, and that's with their DBXL tool.