Discussion about Florida passenger rail operations including proposals. Official web-sites:
Miami/Dade Metrorail, Sunrail (Orlando), and Tri-County Commuter Rail Authority
For Virgin Rail/Brightline: Virgin Trains Worldwide (includes Brightline)

Moderator: Kurt-Trirail

  by Jeff Smith
With regards to use of Miami Central/Brightline's station in Miami, and Tri-Rail's use of it as it pertains to possible Jupiter service: Miami Today
Tri-Rail on Florida East Coast Railway tracks?
As part of the development of Miami Central Station, the construction of two more platforms will allow the immediate connection of Tri-Rail service operated by the South Florida Regional Transportation Authority to downtown Miami and provide facilities needed to support the planned coastal link that will ultimately take Tri-Rail along the Florida East Coast Railway corridor to Jupiter, the resolution states.
  by Gilbert B Norman
Within this AAF related article, there is something Tri Rail related that, "uh doesn't hold water":

http://www.sun-sentinel.com/news/transp ... story.html" onclick="window.open(this.href);return false;

Fair Use:
...Ultimately, Tri-Rail hopes to run all to way to Jupiter on those FEC tracks but the commuter service will need a new bridge built over the New River in Fort Lauderdale and that could cost upward of $40 million, by some estimates

While likely from Day 1, a strong case could have been made to have had Tri-Rail routed over the FEC (FEC freight traffic over the SAL?), that window has long been shut.
  by chrsjrcj
I believe the Northwood connection (north of the WPB Tri-Rail and the WPB FEC Yard) is supposed to be re-constructed sometime in the next couple of years. I could've sworn I read talk of sending FEC freights down the ex-SAL with a new connection at IRIS...maybe I was dreaming it.

Anyway, the New River bridge is probably the most challenging part for Tri-Rail on the FEC. I am very optimistic of Tri-Rail service from MiamiCentral to FLL Airport (and maybe even up to the government center just south of the New River). However, that river crossing is the most challenging part. The NIMBYs would fight a high level bridge like the current crossing Tri-Rail uses on the ex-SAL, and tunneling would probably be cost prohibitive (US-1 does currently tunnel under the waterway in Fort Lauderdale, so it's not impossible).

Seeing how north county reacted to AAF, I'm not as optimistic on service to Jupiter.