This is a wonderful, exciting, and outstanding episode and clearly starts a new story arc of b-stories that will take use through the end of the series (hopefully not for 20+ years) and beyond (revisits). While I've always wanted to see more of Angel (e.g. movies, revisits, etc), clearly Booth is David Boreanaz's calling.
This episode gives us both a wonderful crime and investigation drama and raises the typical b-stories to primary grade this time around. We really get to see the inter-workings of Booth, Bones, and their friends. We also see the various levels of each of them and how they are both close and in some cases, not so close. It is wonderful to see the writers didn't lose anything of their individual personalities when moving them closer together and still has the eye on the bible and are expanding it at the same time.
This episode clearly shows there are miles to go before we need to worry about the end of this wonderful and powerful series. In fact, I'd say only the desire of the actors to move on will be cause to end this massively energetic series.
Bottom line: If you haven't seen this episode, it is a MUST! Go to Hulu, buy the Blu-Ray (when it is available), download it, do what it takes, but don't miss this episode! It is that fun, rewarding, and interesting.