To me, here's what the roster could look like in 2013 and 2014, just factoring in minor leaguers that will have made their way to the majors, as well as guys whose contracts will run out (assume we don't re-sign them). Well, I will assume that they re-sign Ortiz after this year because..well..I'm pretty confident they'll do that.
2013
C - Salty, Lavarnway
1b - Gonzalez
2b - Pedroia
3b - Middlebrooks
SS - ???
LF - Crawford
CF - Ellsbury
RF - Kalish
DH - Ortiz
SP - Beckett, Lester, Buchholz, Doubront, Lackey
RP - Morales, Atchison, Hill, Melancon, Bard, Bailey, Tazawa
2014
C - Saltalamacchia, Lavarnway
1b - Gonzalez
2b - Pedroia
3b - Middlebrooks
SS - Bogaerts (current minor league #s: .284/.358/.478, 14 hr)
LF - Crawford
CF - Jackie Bradley Jr (minor league #s: .341/.452/.510, 6 hr, 22 sb)
RF - Kalish
DH - Ortiz (I am assuming they sign him to a 2-year deal this offseason)
SP - Beckett, Lester, Buchholz, Doubront, Lackey (all under control through 2014...Lester has a 2014 team option)
RP - Barnes (minor league #s: 7-3, 2.30 era, 0.97 whip, 10.8 k/9), Morales, Melancon, Bard, Bailey, Alex Wilson (minor league #s: 5-2, 3.41 era, 1.37 whip, 9.5 k/9)
They have some very exciting young players coming up through the system that I'd really like to see play for Boston. I want to see Matt Barnes, Alex Wilson, Jackie Bradley Jr, Ryan Lavarnway, Xander Bogaerts, Bryce Brentz, and Blake Swihart play for the major league club. They have enough locked-in veterans to provide the framework for inserting these young guys as they emerge ready.
I also think that next year both Beckett and Lester will be better. Lester because (as I started a thread just about him) he's too good to have fallen off a cliff (IMO), and Beckett because it'll be the odd year Beckett. Look at his years by even-odd (ERA only to make it simple):
2002: 4.10
2003: 3.04 (-1.06)
2004: 3.79 (+0.75)
2005: 3.38 (-0.41)
2006: 5.01 (+1.63)
2007: 3.27 (-1.74)
2008: 4.03 (+0.76)
2009: 3.86 (-0.17)
2010: 5.78 (+1.92)
2011: 2.89 (-2.89)
2012: 4.53 (+1.64)
See a pretty remarkable pattern here? So I expect (though I have no idea why this is the case with Beckett) him to be much better next year, and *THEN* they should deal him after that, when he only has one year left on his contract, coming off a good season. He should then fetch something pretty nice.