Please take the below in the spirit of "huge HE fan who appreciates very much the excellent free service he's getting" and not as whining from a freeloader... ;D
Comcast's peering in Miami seems to be pretty lousy in general (seems invariably anything in-state I traceroute to goes via Atlanta or VA or Dallas, etc), and I see there are several other topics on Comcast peering in other locations, so I get the sense this will not happen anytime soon. But, count me as another person wishing this could happen. Or maybe peering with GBLX at Terramark would help, if you don't now?
1 * * *
2 68.85.82.93 (68.85.82.93) 9.497 ms 9.281 ms 8.326 ms
3 po-2-ur01.davie.fl.pompano.comcast.net (68.85.229.146) 10.401 ms 8.802 ms 9.407 ms
4 be-2-ar03.northdade.fl.pompano.comcast.net (68.85.229.141) 10.097 ms 9.938 ms 10.304 ms
5 pos-0-5-0-0-cr01.miami.fl.ibone.comcast.net (68.86.91.81) 10.968 ms 12.368 ms 9.803 ms
6 pos-2-2-0-0-cr01.atlanta.ga.ibone.comcast.net (68.86.86.66) 23.401 ms 26.938 ms 24.857 ms
7 64.209.107.53 (64.209.107.53) 23.905 ms 24.989 ms 25.074 ms
8 HURRICANE-ELECTRIC-LLC-Ashburn.TenGigabitEthernet4-4.ar3.DCA3.gblx.net (64.214.121.170) 39.216 ms 39.973 ms 39.395 ms
9 10gigabitethernet1-1.core1.mia1.he.net (72.52.92.54) 68.715 ms 69.720 ms 71.318 ms
10 tserv12.mia1.ipv6.he.net (209.51.161.58) 71.974 ms 68.716 ms 71.447 ms
(that's actually improved from earlier today...)
Ashburn performs significantly better for me (45ms vs 70ms avg RTT), and even Toronto(!) is slightly better than Miami for me. Atlanta (if you had a tunnel server there... I just simulated by guessing at hostnames and trying 10gigabitethernet1-1.core1.atl1.he.net) still ends up going via Ashburn anyway and is slower, so I guess Ashburn is my best bet for the foreseeable future.
Thanks