And as for the subject matter:
I think I'm going to leave-off assessing Lee until the end of his career. Things could now go either way. If he has a poor year this year and is dropped never to be seen again, he'll go down to me as a two-year wonder. Someone who started their Test career briefly and brilliantly for a year, then had one superlative year 8 years later. And for all the rest of the time was a waste of space. However, if he goes well for the next year and keeps that up for another year or two again, he'll be someone who was rubbish for a long time but managed to have a fine Indian-summer to his career.
Kallis for the last 5 years hasn't been the bowler he was for much of the time beforehand. However, Kallis beforehand was always a confusing presence. He was occasionally devastating, usually on the button, but you always felt he was better than he actually was. He looked like a bowler, but he only actually bowled a devastating spell once a series or so, sometimes not even that. Also, in the last, perhaps, year, I've felt Kallis was bowling better than at any time 2003/04-2006/07.
Flintoff, well, again, a hell of a lot depends on what happens next. Right now he's hard to offer much of an assessment of. He's missed 18 months and has only played 3 Tests since coming back from that, in which he really was same-old-same-old. Looked fantastic, started well quite often, was almost always difficult to get on top of, but in the end just didn't quite pick the wickets you felt he could have done. Hopefully in the next year or two he might do, or might at least get back to where he was 2003/04-2006.