I assume we'll deal Bass and play a core of mostly RR/AB/MT/MS at guard, JG at SF, KO/JS/TZ/(VF?) at PF/C. Even keeping Rondo it's hard to envision more than 30-33 wins.
Milwaukee, Orlando and Utah's cores got better; LA, Philly (I think) got worse or about stayed the same, Kings will be worse if they don't get JSmooth. That puts us in the #3-6 range assuming a few surprises. If they make lottery changes, that should give us a tie for the highest chance at #1.
In the 2015 draft, we have 3 centers (apparently) in the top 4, Towns looks pretty great. Okafor's an offensive force. JO/KO would be offensively deadly and provide great spacing, but may lack defense.
We also have 2 SFs in the #6-8 range if we land a lower pick (Stanley Johnson & Justise Winslow) to use a realistic pick fill a position of need with ideally the bpa and an elite talent.
After next year's draft and summer of financial fluidity, tanking should be out of the question, but given where we are and how our needs mesh with next draft's talent, it's part of the plan this year.