First off, I see Jose being the starter for another 3-4 years (brought back on a cheaper deal). Moving on ...
From the draft: Tomas Satoransky could be a strong talent to groom in a backup role. Yes another Euro, but he is big, athletic, great court vision, and would have another young Euro in Jonas to help get him acclimated to the NBA game. Not to mention Jose, a star euro to show him the ropes. He could be had with a late first round pick or even early 2nd - allowing us to use our higher pick on another area (SF, SG, trade).
Also from the draft, I really like the potential of Kabongo. Selfless, lightening quick, great vision - just needs to slow it down sometimes.
Free agency only shows an unattainable star (Deron), aging PGs (Nash, Kidd) who aren't in the long term plans, and mediocre talent that won't be in our long term plans for a starting PG.
The trade market could be very interesting if we move our 2nd rounder, Amir, or Bayless (pre-deadline). Players like Bledsoe, Dragic, and Flynn maybe ... low risk.
Sessions would be a great backup, but not a starter for the future.
Stuckey has some potential as well.
I was really high on Avery Bradley the year we went with Ed. He was injured in his rookie year, and has yet to get major minutes. If Rondo is staying in Boston, there isn't much future for another young PG to ever get an expanded role.