It is really up to you. If you intend to travel a great deal with the unit a warranty may not be a bad thing to have. Then again you may end up upgrading to something else before the warranty expires. As for me, I never get them for my personal items. I have so far not regretted my choices.
I want the surface, yes. Warranty, dunno yet. If I'm moving it'll be in my backpack unless in needed to check something on the bus. However, on campus, library, or in coffee shops i don't see much risk for damage. That's why i'm indecisive.
Are you American? I don't know if it's different over there but here in the UK, I'm simply covered on home insurance for anything worth up to £1,500 outside of my home. So, I have no need to bother with warranties. Sure, it can take some time to get your replacement but when my iPhone was stolen I got a new one without too much hassle.
Of course, if you spill your beer on it or the keyboard…the product warranty probably won't be much help. Likewise if you happen to just drop your backpack or book bag and the Pro takes a lick, the warranty won't help you out. Warranty is one thing, but protection against hazards is something else. Your Homeowner's insurance may help since it is something you own—it falls under contents coverage—but there is a limit (usually) for electronic items, and content items are usually only covered for specific perils (spilling beer on the Pro wouldn't be a covered peril). Since you live in Canada I'd check with my insurance agent/broker to find out exactly what my Pro would be covered for in the case of an accident.
Just my opinion, but I purchased the 2 year extended coverage- which does cover up to two replacements (at least in the US), even for accidental damage. In two years, less a couple of months, I'm going to complain that the battery isn't lasting as long as it should- I explained this to the MS rep at the MS store where I purchased the coverage. I usually don't buy additional coverage but given the battery isn't user replaceable...