Java, no I don't believe so, as Penguinbait's KDE is essentially a replacement window manager, and therefore is subject to the exact same Java issues as the stock Matchbox WM

However, the KDE based risk clone I pointed to *might* run under the KDE version on the tablets if re-compiled correctly.

I'm by no means an expert in compiling for the tablets, but It might work (especially if we used an older build targeted towards KDE 3.5.x, the current release is targeted towards KDE 4.1)