I see a lot of talk on these boards about HB being "the end" for their characters. While I'll admit that you couldn't ask for a better send off for some well loved characters, I'm rather shocked that more people don't want to explore the possibilities this amazingly designed plot offers.
Just like someone mentioned earlier, HB can be the -beginning- of a campaign. We've been playing the same campaign for nearly 10 years and, while I won't bore you with the details, up until HB we pretty much rotated the same 12-15 characters amongst 5 people. The characters, incidently, were organized into a loose "Shadowrunners network", and aside from a violent blood feud with the Seattle Yakuza (The leader of the group is an ex-Yakuza assassin who brought great dishonor to Shotozumi-san by leaving his service), had not engaged in any truly "epic" gaming. (Well, some of the characters themselves had somewhat epic backgrounds, but that's another story)
That all changed with HB, about 6 years ago. It was the first campaign I personally ran (The guy playing the leader did most of the GMing), and I went absolutely nuts with it. I liberally changed a few things, tailoring the story to the group, but it mostly remained the same. My group had never encountered anything like it, and it was our first introduction (IC -and- OOC) to the Horrors outside of Earthdawn, and we absolutely LOVED it. The game became, very literally, the crux point of our entire gaming world.
By the end of HB our "Shadowrunners network" was basically being held personally responsible by Harly for the safety of the Bridge. About half the group, unable to cope with that kind of responsibility, left under a bad cloud. The remaining half resolved to live up to the Oath to their dying breath. It was probably the greatest moment of drama I have EVER GMed, and I was amazed at what it drew out of my players. This stuff was, in all honesty, as good as any movie or novel I've ever seen (Better than most of the SR novels, but that's another story).
A little sampling of what HB has wrought on our world:
The Collective - Nine feet tall, mutated, filled with hate, and powerful enough to spit in a Blood Mage's face, these 100 guys and girls are the survivors of Thayla's city. They were preserved by the Enemy as a sort of experiment, and resent not only their captors, whom they are forced to serve by their slavery to their own bloodlust, but metahumanity in general for having the freedom they do not. These guys are a nice way of keeping the gaming "epic level" without resorting to the really stupid dragon hunting common amongst other high powered games.
Stam - The "Shadowrunners network" has since grown into an organization known as Stam. Counting ~150 members from across the globe, with chapters in Seattle, Hong Kong, and London. Around 40 of these guys are statted and, between 10 players, we play all 40..... often. On the surface Stam is nothing more than what it claims to be, akin to a Shadowrunners Guild, allowing top talent to subcontract out. Deeper in it is led by the original members, those who took the Oath, and they are constantly scouring Stam's ranks for those who show, shall we say, an inclination to being able to handle exposure to the concept of the Scourge.
The Arthurian Metaphor - Way back in HB I laid the seeds of doubt in Zan, the ex-Yak who leads Stam. See, his best friend since childhood and his second in command is a mage named Rune (Played by me, natch). Zan's got a real King Arthur thing going, both in personality and appearance (Weird how he shares an appearance with Mr. Darke and Damien Knight, both of whom look like one of the more popular renditions of Arthur), and he was rather surprised when, in the Arthurian metaplane, the elderly Launcelot, who had betrayed the round table, turned out to be an aged Rune. Further on in the run, and the pictures of the Knights within the Green Knight's castle turned out to all be directly related to other Stam members. Since then the metaphor has been constantly reinforced, with constant paralells being drawn, and though Rune has yet to betray Zan he has expressed a great deal of pride.... not to mention discontent with the way Zan runs Stam....
I aplogize for overly detailing the setting this way, but I really want to reinforce how much potentialo HB has as a -new start- for your team. It's a wonderful way to have your players enter into the larger SR world as more than just pawns or passive observers, but as influencers of the world. NERPS does
-not- break down at high levels, despite what people might tell you, and we have had ENDLESS fun with the the various tiers of Stam's power, from the average runners with 1-6 kp, to the original team members (Those who are still alive) with "OH MY GOD" levels of power and 20+ karma pools (We use a slower karma pool rate after 10 and 20, incidently).
And, in all honesty, this isn't even a hundreth of the things that have taken place in our campaign thanks to HB. I picked 3 things at random, but thanks to HB every single character in Stam who knows of the Scourge, from 1 kp to 25 kp, is deep, interesting, and more involved in the world than the typical "runners". Harlequin's Back is, without a doubt, the best adventure ever published by FASA, and gives a GM the power to truly use every element of the SR universe for everything it is worth.
Immortals, dragons, Mr Darke (Who, apropo, is one of the biggest villains in our campaign).... what good are these elements if you can't use them as anything except "Ohhhhh, don't mess with these!". I'm not a power gamer, nor are any of my players (Or the other guy who GMs), but I do understand how power can be used and managed responsibly. Harlequin's Back, and high powered running in general, should not be seen as a swan's song for the team. It should be viewed as the open door to a whole new kind of game, the kind which can turn grizzled veterans of 30+ shadowruns into true heroes....
But, then again, I could be wrong.