Grabed the server yesterday and I'm afraid there are number of serious issues issues.
1. The example server.cfg is totally broken. It uses "set" for all the variables instead of "seta" which is required for it to work. While this is easy to fix it took quite a bit of effort to figure out as the last thing you expect is the example config to be broken.
2. The servers fail to startup fully in internet mode reporting "No Steam Master Servers found. Server will LAN visible only."
Update @ 16:52 08/11/2011 - This is fixed by copying Steam.dll from your steam directory to the dedicated server root directory and restarting the server.
3. The core variable required to run multiple servers from a single install, which is required by all server providers, appear to have been removed.
The setting in past games have been: fs_homepath and fs_localAppData
4. Apparently ranking isnt available on dedicated servers which makes them pretty much pointless.
5. cmdlist and dvarlist has also been removed making it very hard to check that config settings are valid
6. The server is huge 14GB, basically its a client install. Compare this to BF3 which is 1GB. There's no need to have a server include all the graphics, sounds and even cut scene movies.
7. No documentation at all that I can find. Again this is readly available for BF3 so why not MW3, its not like you guys are new at this.
8. The dedicated isnt availabe via the steam dedicated server download tool only via the client, which makes it very difficult to support. This is easy to fix and needs doing so ASAP.
9. Server randomly fails to start due to "lack of bandwidth" even when this is clearly no the case. The error message seen is:-
"Invalid server configuration - insufficient upstream bandwidth 0 kbps for 18 clients. Minimum 566 kbps required."
10. net_ip doesnt work. This needs to change the address binding for ALL ports and doesn't
11. Some times the server will insta bin on startup. Restarting it with no changes often just works
12. Server has no logging option, thats been found. This makes diagnosing issues like the above next to impossible.
13. Invalid / broken cpu requirements check sometimes reports things like the following, the check should be removed.
"Invalid server configuration - insufficient cpu performance 3.0252 ghz for 18 clients. Minimum 6.0000 ghz required."
14. DLC maps are not available in the dedicated server download. The relavent files need to be copied from a client with the DLC for it to run the new maps.
All other developers work closely with GSP's such as ourselves, who have over 10 years experience in running dedicated game servers, to ensure that things like this aren't missed; so why does Activision / IW etc ignore this and end up releasing a product which misses the mark?
You guys make great games but we know what it takes to make a good dedicated server, talk to us guys we'll help ensure these basic mistakes are avoided 
So the questions for the devs:
1. When will the steam master servers be fixed or is this error not really an issue?
2. Is there another way to multiple instance servers from a single install, or when will this be fixed?
3. When will the dedicated server be available via the steam dedicated server download tool?
4. When will all the unused resources be removed from the server so its not basically a client with a different .exe
Updates / Fixes
16:52 08/11/2011
The "No Steam Master Servers found. Server will LAN visible only" is fixed by copying Steam.dll from your steam directory to the dedicated server root directory and restarting the server.
20:00 08/11/2011
Added issue #9 about server failing to start due to lack of network bandwidth.
22:02 08/11/2011
Added issue #10 about net_ip not working
Added issue #11 about server insta-binning
Added issues #12 about server having no logging capability.
00:54 10/11/2011
Added issue #13 about invalid cpu check
14:48 26/05/2012
Added issue #14 about DLC maps