I would be very dubious that it has (in the sense of the proof of existence of a polynomial time algorithm). While it is not impossible that the paper is correct, there are a number of warning signs:
- The author has not published the result in a peer reviewed venue (even after 7 years).
- The author does not seem to have published anything else, anywhere.
- The paper presents the algorithms, but the claim of correctness is an informal handwaving argument about the complexity.
- For a problem that has resisted the attempts of some very clever people, the maths in the paper is too simple.
The author doesn't appear to be affiliated with an academic institution. The new version of the paper clarifies this.
Again, without someone identifying a flaw in the paper, these are not fool proof signs. Maybe the author had a unique flash of insight and then moved on to a completely different life, but the weight of probability is against it - extraordinary claims require extraordinary evidence.
To elaborate on (4) given recent news, László Babai recently claimed a major improvement on known graph isomorphism algorithm (no preprint yet, but a decent running commentary on his public lecture can be found here), giving a pseudo-polynomial time algorithm. Babai and his colleagues are definitely very smart people, and the mathematics used to obtain this result is difficult, deep and spans graph theory and group theory. Given the weight of probability, this is the expected level for a significant advance on a problem like this.