Latest news on the Charm City Circulator is that the Purple Route from Penn Station to Federal Hill will begin service on Monday, June 7th. Ridership has been above expectation for the current Orange Route, so the North-South Route is hoped to build on this success.
The Purple Route should be beneficial to travelers coming into Penn Station who need direct service downtown, giving an additional option in conjunction with the Light Rail and MTA Buses. The southern end of the route, into Federal Hill, will be the most helpful in my opinion. Federal Hill is notorious for having limited parking, and ideally the Purple Route will ease this pain for residents and visitors who are looking to shop, eat, or drink in the neighborhood. I can also see the benefit for Federal Hill residents who work downtown.
I walk this route frequently on my way back from work, so if I see any of the station kiosks going up in the next few days I'll try to snap a picture or two. In the meantime, consult the website for updates. I have not seen any yet, which is odd since the new route opens in 5 days. All other news I've seen has been from the Sun, Daily Record, and word of mouth. They need to work on their PR.