Why new Python 2.5 feature "class C()" return old-style class ?

[Ant]

(OT) I don't have the same issue with Syntax highlighting, and I use
jEdit as my main Python editor (Though some of the dedicated Python
IDE's have some nice refactoring/code completion stuff, none has the
raw editing power of jEdit).

I'm using jEdit 4.3 pre3 - though I don't recall any problems with 4.2
(and it was only a week ago I changed). The Jython plugin enables
Structure browsing if you haven't already got it installed.