A great phone, with good specs, software updates and security patches garanteed until late 2018 directly from Google as they are published... I say yes. I just got the 128GB Pixel so I am a bit biased but I didn't hesitate one second.
The newer phones are, well, new. So the Pixel 2 will probably be seducing and all but you don't know how it will be. According to rumours, it will be packed with new things as far as hardware is concerned. Now remember the price of the Pixel at launch? Imagine how much the Pixel 2 will cost at launch with all the new stuff added!
As far as other new phones that came out this year, say the S8, once the new factor as passed you have to still have a great phone. The Pixel will stand the test of time as opposed to the S8 simply with its software (the S7 got Nougat in March 2017 and has had very few Samsung app updates since the S8 came out). Given Samsung's history with updates, chances are the Pixel is going to get updates faster and for a longer period than the S8.
That's one of the main reasons I got the Pixel. I'm a huge stock Android fan and I love getting the latest and greatest in software more than good looking hardware (because, frankly, the Pixel is bland and dull in that respect).
So all of this to say definitely go for it!