^Technically, all that was established onscreen was that there was an admiral named Archer who had a beagle. They never mentioned the admiral's first name. It could've been Jonathan Archer's son/daughter/grandchild. Which is far more probable. Human lifespans in the 140s are credible in the TNG era, but it would be very unlikely for someone of Archer's generation.
Anyone who hadn't been exposed to a Augment/Klingon virus maybe. That might alter him slightly and we've already seen the likes of Kang, Koloth and Kor live for well over a century. Assuming they aren't already supposed to have that kind of lifespan, maybe there's a side effect of genetic engineering involved.
I believe there's a record of Roberto Orci saying it was supposed to be a tip of the hat to Enterprise's Archer himself. Over at TrekMovie.com, if I'm not mistaken. If the author's intent isn't canon enough, I don't know what is...
I basically see Archer as having two fates:
Prime Universe - something connected to the launch of the NCC-1701 affects him and causes his death. Just being able to let go after giving the ship his blessing, I suppose. There's nothing more than a slightly romantic notion in that of course.
Alternate Universe - No Enterprise launch in 2245 (Damn you, Nero! *shakes fist*) and he lives on a good decade longer. Long enough to see Scotty dematerialise his dog forever at any rate and that's the straw which broke the camel's back. He promptly dies broken hearted instead!
---------------------
I notice there was some discussion earlier in the thread about "Minefield". Towards the end of the episode, more than one ship decloaked, didn't it?
At the point this episode was written, we'd been given a strong hint in "Shockwave, Part II" about Archer and the Romulans. Daniels knocking his hand away from reading a future book about the topic.
Now factor in the Temporal Cold War and I'd imagine the plan (prior to Season 4's "Storm Front") was to eventually have Romulans shown receiving a helping hand from the future. Just like the Suliban, the Xindi... even a bunch of Tholians seemed to be acting under instructions at one point.
Maybe "Future Guy" was trying to change the balance of power enough to give Romulans an advantage, using the Suliban as a third party. Destablising the Klingon Empire was his first attempt afterall. Although admittedly his efforts in "Cold Front" and "Shockwave" also required Archer to continue living in the 22nd Century, to witness whatever the end result would have been. It's a bit difficult to see how a character from the 29th Century could hold a grudge against Archer. The Federation as a whole. Certainly. Given the timescale, it would be as absurd as me wanting to prevent America declaring independence from Great Britain, just so I can see Benjamin Franklin or George Washington admit defeat!
Although maybe Archer is more like Thomas Jefferson, since he was at the declaration and later served as President.