I think it will generally be good for Russia in the short term. The possibility of getting involved in a protracted war that is costly in lives and treasure is low. They'll come out of it with increased prestige and a neighbor indebted to them that they theoretically will have some influence on setting up borders and trade concerns to their own liking. Long term it's hard to say what this effect will be. Russia in OTL didn't become the big scary bear that Europe was ready to unite to oppose until the 20th century. They could be painting a target on their back much earlier here. Or they could simply secure all their borders since they have friendly powers to the south already and have a chance for unprecedented internal development.
Earlier, even by the mid XVIIIth century there was fear of what Russia could do , altough that only became fully apparent by the XIXth, especially with the Crimean War and it´s effect of the general populance state of mind of the other european powers.
Altough, since Europe is still preoccupied and will be occupied by the Big bad Triune "lion,", the same way it was opposed to France in the XVIIth century, and Russia is on it´s way to oppose them, they will certainly have a honeymoon period with the other powers in the way of "the enemy of my enemy is my friend".