Hey Truthman,
MTH has blown on the 1:32 scene by rolling out a ton of new one gauge products and offering a slew of the more larger and iconic engines that up till them selling them no one else had the guts to make unless it was $3000+ in brass/all metal. By offering so much product since their appearance in 2003/2004 I would say they are definitely committed to the scale. As far as history further back, they've been in O guage for sometime which is their bread and butter.
As far as their base, I assume by saying small we mean how many are running DCS. Well again they've only been on the market for 4 to 5 years so it will take time. There are still many that have never heard of DCS. I think their customer base as far as folks buying their engines is pretty decent as I understand their Big Boys are just about sold out now and they had multiple production runs. I ordered three all at the same time and they sold out of the first production run before I got my third one and actually had to wait. I think to some degree they have limited themselves with the 1:32 scale as many in largescale model 1:29 so to some degree that may contribute to them being a little obscure in the minds of some. Not to me obviously as over half my motive power is MTH steam.
I don't have any concerns about MTH's longevity, they'll be around for some time to come. They are obviously flush enough with cash to fund two new product lines, HO and One Gauge and control system upgrades to include DCC in their new Protosound 3 boards. When you look at the other Largescale companies out there, MTH has introduced more product in a shorter period of time than any of them. So again, don't worry about them disappearing tomorrow...
Raymond