These plans have been in the works since at least 2005, but have had a lot of problems because of the neighbors and business owners. However they are in the second year of a two-year study into the engineering and feasibility of this.
Personally, I think its a great idea. Getting back to the old days when Baltimore was a streetcar city. This sort of thing has clearly worked for Portland, why not Baltimore! This will be a great way to connect the different institutions along Charles and St. Paul. Cleaner and more friendly than the buses.
The only thing I want to see from this is, if they are going to have MTA fares, make it easily transferable to the Light Rail and Metro! PLEASE.
This is definitely a step in the right direction. Great for college students, commuters, and especially tourists. Hey, want to go to the BMA? Sure! Well just hope on the Baltimore Trolley! Maybe, down the road, we'll see one go down the Key Highway corridor to Fort McHenry.