The folks at JetBrains released a new version of ReSharper today. You can download the new version, ReSharper 4.1, from here. They state that they improved ReSharper to work better with Visual Studio 2008 SP 1, they improved ReSharper's performance, and they added better ASP.NET support.
One of my favorite features is the XAML based refactoring. I do a lot of Silverlight and WPF programming so its great to have their refactorings in place with XAML in addition to the VS intellisense. I try DevExpress’s tools about once a year hoping it will challenge R# for me, but it just has not given me reason to replace R# yet. Until it gets all the features of R# with the code analysis, pre-compile, etc to the level that R# does, I am sticking with R#. But I am rooting for DevExpress to pick it up … they certainly have some nice eye candy in their app … and they’re plug in support is superior to R#. But those are ancillary to me. I need the productivity gains of R# that so far DevExpress has not reached IMO.