I would hate this trade. Rondo is a better basketball player than Drummond, and has a reasonable contract for two more years. Drummond is on his rookie deal for three more years, but then either he gets a max extension, or he hasn't played well enough to deserve it. Assuming Drummond pans out, you save big in salary for 1 year, and then a little in the following years.
Now maybe if we get Bledsoe and sign him to an extension that is less than what Rondo is paid for the next few years I would feel differently, but otherwise, no thank you. The risk far outweighs the potential reward.
Just out of curiosity? What kind of contract do you think Rondo will agree to in 2 years?
Supposing some salary cap inflation, a first year max contract would probably be a title shy of $18 million a year. We can debate if he's worth that or not, but that's the ceiling. Drummond that year would be much cheaper, I whole-heatedly agree. But this year a max player at Rondo's experience is only $2.5 mil more than the first year of a an extension off a rookie contract, so in year 2 of Rondo's extension, he'd likely only be paid at most $3 mil more than Drummond, if Drummond pans out. To me that's just not worth it, unless you think Drummond is a near-certain Hall of Famer.
Again, if you get Bledsoe and he's willing to sign a less-than-max extension, it's a different story. But Rondo-for-Drummond on our current roster is a steep price for potential over proven production, with only one year of true cap relief.