In TV, the realization of a romance between the two leads is one of the ultimate forms of fan service, but it can also be the end to the key source of dramatic tension that served as one of the main reasons why audiences continued to tune in. The will-they-or-won't-they question of romance – which, in the case of Bones happened to be Emily Deschanel and David Boreanaz, or Brennan and Booth, respectively – drove so much of the show's narrative (after season 2 or so) that the gruesome crimes investigated by the staff at the Jeffersonian came in a close second.
But like Moonlighting, Lois & Clark and so many other shows that have come before (and will likely come again), Bones is suffering from the inopportune loss of drive caused by giving fans exactly what they wanted. It's the television version of damned if you do, damned if you don't, as Bones couldn't have gone much longer without directly addressing the Booth/Brennan dynamic. But now that they're almost a married couple (provided a serial killer doesn’t screw things up again), the show isn't quite sure where to harvest that weird palpable energy that came from the flirtatiousness of its two leads.
Thankfully, the show is smart (all ridiculous product placement aside) and perhaps those smarts will translate into finding the same kind of humor and liveliness once supplied by the question of romance in the banality of inevitable domesticity. We can only watch and find out.