Heh. Dropping, eh? Good for Privateer Press.
Not really. Miniature sales are dropping across the board. Monsterpocalypse's next set is in limbo, WotC ended D&D Miniatures, and Rackham is in liquidation.
Now if we give it another ten years, maybe we'll see a relevant competitor shake up WotC. Har har.
I hear Pathfinder's got them sweating pretty good. But since Hasbro swept the company up, the PnP end of things hasn't really been WotC's focus. It doesn't have a collectible or game-y quality like the rest of their products. You can't re-buy a handbook you already own and you have to use your imagination rather than a card you can buy in a booster.
oh wait
Well, I know Privateer's been doing okay (as in they're not in any danger at least and may even be expanding a little). It's only anecdotal, but more and more I hear Warmachine/Hordes as folks' first choice for getting into tabletop gaming.
The most basic difference is that the production quality is as good as GW, but simply requires far fewer models to play. Entry-level play is simply far less daunting.
If GW is sinking and PP is at least staying flat (or even growing a tiny bit), I would say they are the main threat, yes. The smaller game companies like Rackham aren't really a factor - hundreds (maybe even thousands) of companies have come and gone in the past 40 years that produced minis that could be used with any rules of your choice (i.e. they just produce the figures. Sure, some have their own rule sets, but really the following for those is so small and localized that even if they hadn't put out a rule set, it wouldn't have made much difference to their overall bottom line or market share. tl;dr: The bit players are functionally just minis companies, not game companies.
I've said it before, but Magic is basically comparable to Warhammer in the regards that it has a reliably large playerbase, is monolithic and stable, and has a long history (and the ccg world's only remaining tournament system with relevant prize payouts). But again, like Warhammer, it's seen as a rich kid's game. Or at least a pasttime you have to sink large money into. I mean, gripers have been saying that for nearly 20 years, sure, but for most of Magic's history when you
really looked for yourself, you could see that wasn't true, that there were several affordable tournament formats. Now, not so much.
Magic needs a real competitor again, something to shake them up and scare them. But I doubt we'll see one anytime soon.