I think its both to fill the gap and a small system seller.

So I expect it to do 2 million on Ps4...

Just saw an interview where Bruce Straley and Evan Wells said they didn't even think the port would go anywhere, but they saw all the fans saying they wanted a ps4 version so they doubled down on getting it ready to release.

But yes it's a bit of both. Any game is going to fill a gap obviously and it won't be a huge system seller but it will sway quite a bit of people to get a ps4 I think.

i can see a 10-20k bump the week its released. i mean, the game might move systems but TLoU aint no knack.

yeah at most 30k I think.  And hell naw it ain't no knack.  Knack kicks TLOU ass in story and gameplay!!! :-p

They could of saved this for e3. Start by showing the next last of us dlc then at the end have the ps4 logo

By that time it's close to being released, if not released already. Also, there were so many 'leaks', even it being in the US PSN Store, that they basically had to announce it.

too many leaks happened. also, E3 we will most likely see uncharted, so that would take some hype away from this. better to announce it now, since the leaks happened, get people hyped and then continue riding the hype train with E3 up until release. 

Filler
its what some want
sets up the PS4 owners for Tlos2
Another mil in sales
builds up the franchise some more.

Not sure

They are a lot of PS4 owners and possible future owners that either didn't own a PS3 at all and/or play TLOU

I don't see people picking up a PS4 just to play TLOU when they didn't get a cheaper PS3 to do the same.

Does add to the PS4 overall for those considering purchasing the console though

I think it's mostly filler. I don't see people going out and buying a PS4 to play TLoU Remastered. It'll still sell great though.