Honestly i don't think Vayne is all that OP... then again, i play Brand a lot and can usually shut her down with a well placed stun, or at least get her to back off with my other abilities.
As most of us 'seasoned' LoL players know, good CC wins ANY game.
And this is especially true for the hard-hitting yet fragile-as-an-egg Vayne.
My problem is the fact that her silver bolts either cost no mana, or not enough (not sure which, as I've never played her).
Seeing as a lot of people equate her to a variation on Ashe, I think that the only 'nerft' that should be even remotely considered is to charge Vayne a certain amount of mana per use of Silver Bolts, much like Ashe's Frost Shot. Vayne being able to spam Silver Bolts with little to no cost is just plain silly.
Lets face it, how often does Vayne really use her mana? I can't recall a game with or against Vayne in which i noticed her mana low, or OOM. Due to the cooldowns on every other abilitiy that actually requires mana for her (knockback, roll, ulti) she always seems to have ample mana for really no reason. This could easily be countered by charging her an amount of mana per bolt-fired of Silver Bolts... which would in turn, force the Vayne players to be more cautious of how many [silver bolts] they are spamming on minions, turrets, etc.
This would also cause Vayne players to consider getting some type of mana replenishment item, even if its only a Manamune. Doing so would also require players to decide on going for pure, high output damage items, or to supplement the cost of spamming Silver Bolts on every minion, turret and tree in the game by having to get some mana regen.
Like i said, I'm not even sure if she goes get charged per use of Silver Bolts, but if she does... its not enough. Just look at Ashe, she has to get mana regen if she expects to spam frost shot on every single attack.
If your just going to spam some useless troll response to this thread, don't bother. If you have an educated opinion for or against my argument, by all means please reply.