I wonder if this kind of finish will last forever or it will wear soon or later. If the second option is right, how long it will take?
Thanks in advance for replays

Welcome to the forum.
The finish will wear out in spots over time depending on how much you play it, and bending strings will probably speed that up a little. Professionals who use a certain guitar of theirs more than others they own would be a good example. Take a look at this YouTube video :

http://www.youtube.com/watch?v=Fa4gm24w-r0

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Though to be sure, polyurethane is the hardest "mainstream" guitar finish and will take far longer to wear through than nitrocellulose. Which is why Fender use it on all their necks regardless of factory of origin - save for some US reissue and artist sig models.

I seem to recall that Clapton wore through the nitro on his "Blackie" fingerboard and had it refinned - twice. That took 17 years before he retired the guitar.

I've seen older necks than that finished in urethane played regularly and with no significant wear.

'Course, some people actually like the wear marks and favor nitro on their fingerboard for exactly that reason. To me, the lacquer is there for a very good reason and I want it to be as hard and last as long as possible. Polyurethane for me...

Cheers - C

Poly necks will wear if you play them long and hard enough. I have seen 80s Squiers and Fenders with nasty wear on the necks. 70s Strats necks were poly too, and plenty of them have wear