In reply to alexm198:
1. Well it depends a lot, it varies each year; 3 years ago, for example, conditions were awesome (gullies, icefalls, ...) in March. Last 2 years there was, however, too much snow, so climbing conditions were sub-par (although persistent people found lines as well). Anyhow, there should be enough snow in the mountains to allow for winter climbing.
2. The climbing community's actually quite developed, it's just not particularly foreigner-oriented. So all guidebooks are in Slovene, etc. Still, I think it's doable to find a climbing partner around here.
3. March is actually regarded by many as the best off-piste skiing month. That obviously means that on-piste skiing should also be good in that period. But mind you that Slovenian ski centres are not as big as the Austrian or Italian ones in the vicinity.