What exactly makes them incomparable? I think it is fairly apt. They were both the "one more thing", both were Apple versions of existing technologies that some people are claiming will succeed mostly cause they are Apple versions, they are really power user features that lack mass adoption currently, both face social mores that make their use somewhat awkward and so on. I think all signs point to Facetime the sequel. A damn good product that is used once or twice to test, a lot by a couple of people, and is mostly inconsequential.
For one thing, FaceTime is a multi-party tool which falls victim to the network effect. The first people to get an iPhone 4 had few people they could FaceTime with, so it wasn't very useful to them.
Siri, on the other hand, doesn't depend on anyone else having anything in particular. Siri would be just as useful if you were the only person on the planet able to use it. I think that will make a huge difference in adoption.
What?! No, certainly not. When FaceTime gets adaption you will not know whether Siri will also be able to get adaption. The reverse is also true. They are completely different features.
What "marketing hype"? Being announced last on a keynote?
People attribute special powers to Apple's "marketing hype" but 99% is web generated --articles, posts, comments, user anticipation etc, not from some Apple's marketing campaign.
Except if showing the Facetime and Siri features in its tv ads qualifies as "marketing hype".
In any case, Facetime is an iOS/Mac feature. Noone expected it to catch as much as Skype, if only because there are like 80% more Skype-capable devices out there (like, say, all Windows boxes).
And Apple even made some bad decisions IMHO in promoting it: no OSX client from the beginning, not integrated with other apps (say, iChat), not promoted for PCs bundled with iTunes, etc.
When you're hiring Oscar winning directors to make the (series of) adverts based entirely around one feature you're well into "marketing hype" territory.
A few people made the sensible point that Facetime was going to have a hard time displacing Skype due to network effects (and Wifi limitations), or indeed being useful at all for many people without large numbers of iPhone 4 using family and friends who they didn't see face-to-face enough. Many others seemed to have forgot that Skype and other such video chat tech such as iChat even existed in their excitement for this revolutionary technology.
A position I feel they were forced into since this was the big finale "one more thing" in an iPhone announcement, and therefore couldn't be considered a bit of a damp squib if they wanted to maintain face.
