So does this mean the end of the Naruto series?
At least by his hand. That doesn't mean he can't sell the rights to others to do so (or change his mind sometime later) or we get something like Dragon Ball GT.
It's just as well, even if he hadn't been murdering the series in the latter half of Part 2, the ending he chose left the series with very few places to go.
There are small side-issues that could be explored, but the ending wrapped up all of the majors ones completely. What major story could be written at this point without basically undoing all that Naruto worked for? By taking the story world-wide and having everyone happy at the end, what is left?