I'm embarrassed to say I've hardly touched 2.6 let alone 3.0 but Let's talk about Python 3.0 has some interesting background on the limitations of Python 2.x as well as thoughts on process improvement
This is a startlingly good analogy for the way lots of corporations do things; once a particular process is entrenched (and especially after a couple rounds of employee turnover), there’s nobody left who remembers why the company does things this way. There’s nobody who stops to think about whether this is still a good way to do things, or whether it was even a good idea way back at the beginning. The process continues through nothing more than inertia, and anyone who suggests a change is likely to end up viciously attacked by monkeys.
Of course CentOS5 still only comes with Python 2.4.3, which is what I'm stuck for much of my development unless is compile from scratch.