It could get really thorny picking blueberries. And the raspberries will crowd and compete. If you want a good crop of blueberries I'd plant raspberries somewhere else.

I agree with fruitnut -- raspberries are much more vigorous, and you will be fighting with them every year for several months on end to keep them from overtaking the blueberry bushes.

Not sure they are pH compatible. Blueberries prefer pH around 5, whereas raspberries prefer around 6. Meeting in the middle might work, but would not be optimum for either. Also, nitrogen requirements are different. Blueberries prefer ammonium, and raspberries prefer nitrate.

Blueberries are a finicky plant for conditions. I would keep them separate if possible, since the plants have different requirements in many ways.