In case you haven’t already watched them, I suggest checking out the Xcode 4 video tutorials published by The Pragmatic Studio. Each of them is short and to the point, and free! Even though I have been using Xcode 4 since it was released, these videos had plenty of useful tips and tricks for me.
After watching some of their free videos about Xcode 4, I invested in the six-part video series about Core Animation: Creating a Compelling User Interface with Core Animation. I’m really excited to watch that series!
This message was not endorsed or sponsored by The Pragmatic Studio. 😀
iJoshSmith 
Thank you!
Like you I’m a long time .Net programmer, I was actually an orange badge on the team back in 2000-2002, and felt the need to try something new. I have to say mobile is really getting my passion going again and I’m focusing on iOS and WinPhone.
BTW, if you are a fan of Resharper you may want to try Jetbrains AppCode. Conceptually it’s IntelliJ for Objective-C but depends on XCode for a few things. The Release Candidate is available now.