I installed the latest chromium build and gears was changed to Gears 0.5.1.0

Did you spot something new?

no

btw: have you seen the bookmark manager before

Yes, that's a feature introduced in build 4191: http://src.chromium.org/viewvc/chrome?view=rev&revision=4191

Other recent Chromium features: options to disable spell-checking and form auto-fill, session restore supports apps and pop-ups.

now it is Gears 0.5.3