I'm curious - is anyone playing the skirmish game?
Yes.

I'm doing so, and greatly enjoying it. There are a heap of scenarios in the Miniatures Handbook as well as rules for a Skirmish campaign (very nice rules, too). You want a certain number of miniatures so that the variety is there. Once Dragoneye comes out it should be very interesting indeed.
If the minis are doing so good, then what is the "business-related" part of WotC killing off the Orc War Party and Outlaw War Party nonrandomized packs?
Because they weren't getting ordered as strongly as they hoped. They were really coming out too late - by the time they arrive, the secondary market will make most of the figures in those packs available CHEAPER than for what WotC could sell them for. Sure, not everyone could take available of that secondary market; but each person who could was another sale lost.
One of the reasons for the canning of the war party sets was almost undoubtedly the poor selection of figures in them. The Orc War Party wasn't that bad, but the Outlaw War Party was nearly useless.
Mike Donais has posted on the WotC boards saying that the canning of these products allows them to work on different ones; he's also asked what sort of theme packs people would like to see... perhaps a replacement?
There's a link on my webpage to his comments. (see my sig)
Cheers!