I've actually been meaning to post this up for quite a while now but am just now getting around to it...
A little over a month ago, the popular strategy guide writer, Dan Birlew, sat down and talked with Capcom about his latest work (well, he was still working on it at that time).
Interview with Devil May Cry 4 Official Strategy Guide Author: Dan Birlew
Nice interview, Dan!
It's good to hear that DMC4 still has the hidden red orb locations. I enjoyed finding those in DMC3:SE. The one in the Tranquil Souls Room was probably the most memorable since I spent quite a bit of time scanning that room over for its possible location.
Anyway, if you're not familiar with Dan Birlew then you might want to visit his site. He has wrote plenty of Resident Evil guides that I have for safe keeping and he also wrote guides for GameFAQs at one point under the username President Evil.
In all honesty, I would pick up the guide for collection purposes, but I'll probably be really pressed for cash by the time DMC4 releases since I'll be buying both versions and I'm going to try to squeeze in Turok around that time as well.