Its unbelievable, but true. Some cracker gained access to wordpress.org SVN and modified files to inject exploit. So anyone who has above mentioned version has got a backdoor in to their wordpress files. I found out when scanned my computer with symantec scanner (security.symantec.com) (read more about it here). Which later I verified with wordpress.org announcment (here) Make sure you upgrade immediately.
It almost as unbelievable that you've only just heard about it. I realise your intentions are highly commendable, but if you had read the links you included you may have noticed it is an 8 week old "news" story.
aaah, silly me. Didn't notice the date. But hey its news for me . I scanned my laptop today and was hit by this. Its scary to see wordpress.org could be cracked.
The exploit code is fairly simple as well. Not exactly a hard crack to implement, and thats whats worrying.