Kent Beck wrote the second edition of his “Extreme Programming Explained” book. The new XP model proposed in this book is very different from original XP (good comparison of old vs. new XP). New XP has 24 practices. Most of the new practices about human factor and business relations. And there are not so many new techies practices (just Single Code Base and Root-Cause Analysis maybe).
It seems that new XP is more adaptive and maybe more, well, “agile”. This is a kind of meta-process that could have variuos survivable implementations in different environments. And it is less “extreme”, especially nowadays.