Not too sure about bugs, but here is a few changes to the Windows Mobile pda UI that I can see:
1) Manage Edit tasks removed.
For server based syncing, accessible from task list -> menu -> synchronization
To view collected features, available from Collect Features task -> menu -> View Collected Features
2) GPS Collection settings such as streaming distance or time, now set for whole project rather than per layer. Not keen on this change, we have different business rules about GPS Collection settings depending on layer.
3) Cooridnate settings, ability to display in map document coordinates, not just WGS84 lat/lng
4) Navigate to... now in app rather than a separate extension. In Map View -> Menu -> Navigate to or from a point feature i.e. from identify or search results list.
5) Complete overhaul of capturing features. No longer do you select to capture geometry and select to capture attributes as separate opertaions.
Click Capture feature, takes you to attribute editing straight away, you add the geometry by editing the uppermost 'shape' attribute.
No longer menus to choose capture type (i.e. map or streaming), takes you straight to map view, which has three buttons below the zoom in and out (if line or poly, draw on map, averaging, streaming) or two buttons if a point. (draw on map, averaging)
Not too sure you can still do offset.
For point features, there is a nice shortcut where if you click below the 'Shape' heading, it just starts averaging and does not take you to map view.
Not yet implemented for lines or poly, this always takes you straight to map.
6) Feature editing, such as replace sketch, delete portion, replace portion. Hurray!
7) Last but not least. Map View, round buttons now square