Or in fact is it more ?
Let me elaborate; I am a big fan of Leo Laporte's TWiT.tv (This Week in Tech) netcast network, I download a whole raft of podcasts to listen on my commute, including This Week in Google, This Week in Windows, MacBreak Weekly and FLOSS Weekly. Now Leo is happy to admit he does not really cover enterprise computing, but FLOSS Weekly quite often does cover software projects that have an enterprise element, and the latest episode covers MindTouch with the guest speaker being Aron Fulkerson (co-founder and CEO) You can download the MP3 and listen to it yourself here: http://www.twit.tv/floss89
I only discovered MindTouch a couple of months ago, and so the timing of this particular FLOSS Weekly eposide was quite appropriate.
Aron describes MindTouch as being an open source corrolary to SharePoint on a number of occassions and even states that SharePoint is their biggest competitor (is it not everyones biggest competitor ?). However MindTouch is a fully web services oriented platform that is only 3 years old, and as such it is not burdened with some of the architectural "issues" of MOSS. Of course it is also open source and standards based, which can be advantages. However don't let the mention of open source put you off if your a MS shop, the underlying business logic layers of MindTouch are built using C# on Mono (the open source version of the .Net framework). Having said that because it is a fully REST-ful web services platform, you can use PHP or Java for example for front end work, so your not limited to C# either. Basically Aron is saying that the MindTouch is way ahead of SharePoint 2010 before it even see's the light of day (well, he would though wouldn't he !). Of course because its open source, you can download the core of the product and run it yourself, for free, and see if it fits with your requirements.
Originally a fork of MediaWiki it appears that MindTouch has become much more, listen to the MP3 to get Aron's description, but it appears that it can be considered as an enterprise mashup platform - a product which can be layered over legacy ERP / CRM / etc..... systems to provide a web based, collaborative, "Enterprise 2.0" gloss layer for these legacy apps. (I love the bit when Aron mentions "Enterprise 2.0" and Jono Bacon says: "eeugh, you just made me sick in my mouth" - you probably have to be British to find the funny......).
So, MindTouch has a good gallery of videos you can go take a look at to learn more about the product, see: http://www.mindtouch.com/Resources/Demo_Gallery
I will complete this post with my standard caveat when it comes to products; there is no one tool to rule them all, make sure you have your strategy sorted out and a truly know and understand your requirements before you move into solution design with any tool !