With majors wallets (10,000s or even 100,000btc) getting deleted would that have an effect on the value? there are less btcs around so the still existing ones are more valuable.
I would say that it has the potential to slightly affect the value. Losing 100,000 would reduce the current amount of available bitcoins by about 1.5%.
But on the other hand, it could also have a detrimental effect on the economy also. I'm going to assume some of the users who lose their coins in this type of event will get frustrated with the system and as a result stop using bitcoins. An even worse scenario would be that they stop using bitcoins, and they also tell all of their friends not to use bitcoins because of how they lost their coins.
In the business world there is a saying that goes somewhat like this. "One happy customer may refer a friend, but one unhappy customer is bound to tell many."