Yeah, a 45mm f/2 would be a nice addition. In the meantime I use an old Canon FD 50/1,4. It's too big, and heavier than it needs to be, but it works pretty well.
That said, my wife has the 14-45 kit lens (the original Panny, since discontinued for the 14-42) and it is excellent. The aperture is a little slow, but for landscape and general use that's not a big deal. Having the entire range of "classic" focal lengths in one lens makes shooting easier and faster, and prevents dust spots on the sensor from repetitive lens changes. For travel and hiking this lens makes a good combo with the 45-200 (also a very nice lens, especially given the low price), and the 20mm for good measure.
If you need a very wide aperture for creative depth of field control, or just low light shooting, then the 14 and the 20 are a nice combo. I carry both -- one on the camera and one in my jacket pocket, or in a small waist pack when hiking.