Honestly, it's hard to tell. Even a lot of people who are the more casual gamers, and people who I've seen stop in to who are fans of other sports titles but were thinking of switching seem to be on the fence from some posts I've seen.
I generally feel pretty frustrated with the way things shape up, but in the end i usually end up purchasing. It's slowly pushed back. It used to be a pre-order, and midnight pickup, then it became a release day pickup. Last year with 14 i played them demo for a bit and was on the fence, but got frustrated on my Xbox trying to update rosters, and ended up grabbing it about a month after it came out, but with NHL15, I'm honestly probably not going to buy it, at least not without it dropping to around 30. I don't have a PS4 yet, and if i did grab one The Show would be an almost instant purchase, but on my PS3 i'm doing just fine with The Show 13, and haven't touched NHL14 in months. There's definitely no way i'm grabbing NHL15 on PS3 as it's looking to have even less to the game than the Next-Gen release, and certainly not worth the $60 tag.
EA seems to be having some trouble with this release, and it seems to be more than usual. I've seen more people than usual who are planning to not get it, or wait for reviews. There's always a few people who generally don't want the game, but end up picking it up at release anyhow, so we'll have to wait and see. But, personally, i think NHL15 could take a pretty significant hit, especially with the online modes that i'm sure a lot of friends convince their friends to pick up the game for.