big.LITTLE is a gimmick? If the new Exynos was a true 8-core chip, then yes, it would be a gimmick, but alas it's a 4(A15)+4(A7) big.LITTLE arrangement meant to save battery during basic tasks, and dish out power when it is needed.
A bigger battery is ALWAYS useful. No top-tier/flagship smartphone should be released without a ~2500mah battery.
Ultrapixels, yeah, gimmicky title, but not a gimmick in function. A 4MP shot is a 6"x8" in print form, and plenty big enough(2400x1600px) for sharing on the web, even with some light cropping, you're still able to fill a 1080p display. So a 4MP capable of taking in more light per pixel, should result in better clarity/quality in a wide range of lighting conditions. 13.1MP cameras, that's a gimmick, because at 300dpi, you're printing out a small poster(~0.25m^2). Anything >8MP is a gimmick, at least as far as phones/P&Ss go, unless of course you're ABSOLUTELY awful at taking photos and need to crop to 1/4 of the size with regularity.
The UI itself on both the HTC and Samsung, is something I could do without, but there is no denying that some of the features they are bringing to the table, will be further refined over time and implemented on all Android handsets. So by that fact alone, I like that they have continued using their own custom skins for Android. And kudos to Samsung for releasing a flagship device with the most current version of Android, hopefully this spurs other OEMs to do the same.
This all said, I'm still waiting for the 'X-Phone' from Googorola.
Also, I will assume K. meant revolutionary, because by their very nature, incremental upgrades ARE evolutionary.