If anyone is confused by this let me help explain it.
With KG and Ray expiring at the end of the season (and Pierce still on the books) we could potentially have roughly 20-24 million in cap space in the offseason (after our two 1st round draft picks). That 20-24 mil in cap space is only obtained if you renounce the bird rights to KG and Ray. So... you could theoretically sign Dwight Howard to a contract starting at 20 mil... but then you are basically saying goodbye to Ray, KG and i'll add Jeff Green as well (unless they sign for the vet minimum). There would be no money left.
So you can head into the offseason and feel free to split up that 20 million however you'd like. POSSIBLY the 20 mil is just enough to re-sign KG (7 mil), Ray (7 mil) and Jeff Green (6 mil), but I doubt it. KG might retire so maybe you just split the money between Jeff Green and Ray. Maybe you split the 20 mil with a couple signings (Jeff Green 10 mil, Greg Oden 10 mil) and say goodbye to Ray and KG. The main point is... you are NOT going to keep this team intact and add a superstar. It's not possible.
So this is why we are seeing hypothetical Paul Pierce trades. Pierce makes 16.7 million next year. If you traded him right now for Amundson (expiring 2.7) and Paul George (2.6 mil next year), you would be freeing up another 14 million dollars in the offseason. That's significant.
What it means is that you'd have 34-38 million dollars in cap space next year. In other words, enough to theoretically sign Dwight HOward to a 20 mil contract AND have 14 million left over to doll out how you see fit (another impact star?... bring back KG and Ray on cheaper deals?... sign Jeff Green?... ) It offers more flexibility for our rebuild.
As for Paul George... Indiana fans seem to think he's a phenom. He was the #10 pick last year. He's turning 22 years old in May. A 6'8" 215 pound SG/SF. I have to assume that if you guys are anything like me, you have never paid attention to Paul George play (maybe you saw him a couple times against Boston at the most... not enough to generate a worthy opinion). So I can't really judge him. I'd link you to a highlight video, but that would be pointless (you can make highlight videos out of anyone). Needless to say, it's set to rap music and has him flying all over the place, doing 360 dunks and finishing breathtakingly with authority... so I can guesstimate he has some athleticism that would fit nicely with Rondo's skillset.
If the Pacers were to include a 1st rounder... it would really difficult to pass that up. But of course... the hypothetical Pacers/Celtics trade might simply be a baseless rumor anyways.
There you go... this is why trading Paul Pierce for Paul George makes sense, but trading Paul Pierce for Granger (makes like 12-13 million) or David West (makes about 10 mil) doesn't make a lick of sense.