@KTy: So far I didn't find a suitable routing backend for transit routing. Mapquest (included in Marble already) claims to support transit routing, but I wasn't able to calculate a route with it yet. Possibly it works in quite limited regions only so far.
There's some work by Google and others to have cities contribute their schedules in a standardized way. It still has a long way to go, but may become a good choice at some future point.

@christianko: Currently three of our routing backends support bicycle routes: OpenRouteService, MapQuest and Monav. When OpenRouteService was used, the behavior you describe might occur because in Marble 1.3.2 we don't extract the turn type from OpenRouteService yet. That will change with 1.3.3. You can tell whether turn directions have been extracted by looking at the turn instruction list below the route via points: The icons on the left must be arrows / roundabout indicators, not "i" icons.
The other ones should work fine with voice navigation. Notice that for Monav you need to install 1) Monav Routing Daemon from the Ovi store (free) and also 2) one or more suitable bike maps (see Offline Data in Preferences) for the region you're travelling in.

@all: I expect Marble 1.3.3 to be released at the end of the month and hit the Ovi store few days later. Here's a quick list of the new features:

• Support for bookmarks
• Filtering in offline data management
• Support for OSRM (Open Source Routing Machine) as another routing backend
• Download (caching) of map tiles of the currently visible area

A more elaborated changelog alongside more screenshots can be found in this post.

If you feel brave, give the fresh build 1.3.2.2 a try. Thanks to all testers