Technically, it's a new product offering called the BlackBerry Enterprise Server Express - a scaled down version of the tried and true BES server.  Some of the highlights:

• It's FREE - both from a server and a CAL perspective!!!
• People can use the BIS service, which typically costs less than a BES data plan
• It can run on your Exchange box (so you don't need to buy another server)
• You get many (but not all) of the features available in the full blown version of the BES - this is great mobile device management for SMBs
• There's a web based administrative console (so you can administer it wherever you are)

I think this is a very smart move on the part of Research in Motion.  One of the key points of argument AGAINST deploying a BES server is the cost of the server and the Client Access Licenses (CALs).  By providing the solution for free, RIM is for the most part making this a moot point.  By using other mobile platforms that support ActiveSync, including Windows Mobile, webOS, iPhone, Symbian and Android, organizations don't need (in theory) to purchase a BlackBerry solution / platform.  That argument is now gone.

I'm not going to touch upon the real benefits of the BlackBerry platform, including security and phenomenal IT policy management.  That's not the point of this discussion.  What I do find intriguing about this announcement are the implications of what is NOT being said:

• By giving away a "starter edition" of BES, RIM is focusing on selling more devices. The consumerization of enterprise mobility is pushing more and more individually liable devices in the corporate market. RIM wants this to happen, because that means they sell more devices. However, they also want to tell companies that they need to do something about it. This is not hypocrisy, but instead the continuation of a paradigm shift in RIM's strategy - device sales.
• 35+ IT policies. Certainly a far cry from the 450+ policies available in a full blown BES...BUT, what I do find surprising is that now Microsoft can say that Exchange alone can support 50 IT policies. I would have loved to see RIM say it had 50 or 60 policies in BES Express....just to say it still had more than Exchange 2010.  I'm sure this can be addressed quickly, but it would have been nice to have in version 1.0

There is one other thing.  Regardless of the fact that BES Express is free, there is still a cost to having to install and maintain the implementation.  This is very much analogous to the open source debate - while the upfront cost is nil, there are always costs of adding additional software to one's environment.  I'm not suggesting this is a BAD thing, but I just want to point out that you will still incur costs.

That said, I would have loved to hear about a cloud based solution - both for SMBs and for enterprises.  Here's the one problem with BES Express.  What if your IT administrator doesn't want to install the software...just because s/he doesn't want to deal with it.  Your personal BlackBerry won't be able to benefit from all of the features that are available in the BES.  What if you could have OTA synchronization just via BIS?
 
So all in all, I think this is a smart - albeit potentially defensive - move on RIM's part to mitigate the continued proliferation of devices using the ActiveSync protocol.  That said, this could also be the first step for RIM to market the full blown version of the BES as a mobility management solution as opposed to a PIM OTA synchronization solution that can also manage your fleet of BlackBerry devices.