What’s the ‘unique device identifier’ (UDID) of a non-iOS device like a Macbook Pro running Mac OS X

I wanted to know if the Hardware Serial Number associated with a Macbook Pro is itself treated as a UDID, or is there something else that uniquely identifies the device?

I'll provide a little bit of context that's not completely required but might be useful for those wanting to understand my motivations behind the question, otherwise skip to the last paragraph.

It's been 21 days since my Macbook Pro [mid-2010] running Mountain
Lion was stolen. Despite having several software based
tracking/geo-locating bugs installed on my Disk, it hasn't showed up
on find my mac or any other service that would have sent me an IP
if/when my device accessed the internet [assuming it wasn't wiped].
That really leaves only two options, either my Macbook was never
[inexplicably] used to access the internet since the theft, or it has
been used to access the internet after my hard-disk was wiped. Since I
had no firmware based tracking that would report to me, it seems clear
that it's no longer inevitable that I shall get some information in
the future from my device communicating with me directly.

Assuming the worst, either my hard-disk was wiped or completely replaced with a new one. There is one kind of information, that I am currently aware of, that is definitely still communicated to the Apple servers each time a connection is made to the internet. The helpd service or other apple system modules send anonymous information to swscan.apple.com etc. This anonymous information probably contains the device's hardware serial number along with other details like the OS version etc. Am I incorrect to assume this? Is this hardware serial number unique or unchangeable? I remember my entire chipsets being replaced and still having the same serial number. Where exactly physically, is this Serial? Would taking apart the Mac keep the Hardware serial? Or is there something else that Apple devices communicate to their servers to identify themselves?

I am wondering if this is how UDID is logged, then it's in a database somewhere and then I only need to contact the concerned authorities (law enforcement etc.) to obtain this non-personally identifying information and see if my hardware is still around or if it has been sold as metal scrap.

Thanks in advance. Stackexchange is the last place on the Internet that I still have faith in! I look forward to learning more. 🙂

Macbook Pro Mid-2010
OS X 10.8.2
Original Charger not stolen – [also, apple computers extremely rare so, finding a charger would be difficult]
Last IP connection from my computer made by me to Dropbox sync.

Addendum: Some additional info – I am not in, or from the western world, so non-technical advice about theft-recovery would probably fail to account for the dystopia I am embroiled in. Also, a gentle reminder to not make this a forum for highlighting/preaching good safety practices/appropriate pre-planning or post-theft response. Those stock responses and replies are available elsewhere and I'd hate to get off-topic advice/help. Please refrain from assuming things that I didn't mention explicitly. For example, don't blame the victim, don't assume I don't back-up etc.

Oh, I didn't do a firmware lock, because I didn't want the thief to break and throw away my hardware.

Cheers!