HTC is pulling no punches regarding the new Galaxy S3. It's obvious they took the Galaxy S3 very seriously because of all the hype mounting up around it, and because Samsung is known for making very competitive devices. I'm sure they were very nervous before Samsung's event in London, because they didn't know what to expect, but right now it seems they were pretty happy about it after the event ended. Why? Because they (and many others, actually) think that Sense 4 looks much better than Samsung's Touchwiz skin.
As a hint to Samsung, they've said that although they didn't have much time to work on Sense 4, since the Android 4 OS was already pretty hard to port to their phones, considering it's a major upgrade from Gingerbread, and they didn't have much time to work on their skin, but they were still able to push out a skin that looks better than theirs.
I don't like Samsung's direction myself with the skin. While they kept some stuff from ICS, they still seem to be fighting against Google on this, as if they'd rather stop doing what Google says for the platform, and just do their own thing. I don't like that trend, and I hope some of the outrage that came out with the Galaxy S3 will teach them to not stray too far away from the stock Android experience – or they are dead to their customers. Samsung should take that very seriously, unless they want people to switch over to HTC's phones.
HTC also implied that their skin is better than stock Android is well. That is something we should expect from any company making their own skin, and the truth is that in some ways it is a little more welcoming than the mostly deep black ICS UI. But in other ways, HTC is just changing the skin for the sake of it, even if it is better than Touchwiz. It would be much easier for everyone, including consumers, if they just used stock Android. Chances of that happening any time soon with any of these manufacturers are pretty slim, which is why I'm hoping Google will really use Motorola for this, to push a ton of stock Android devices on the market.