WhatsApp s coming to BB10 this month. Skype has also said they will be bringing it to BB10, however, we don’t know when.
If you want a BB10 device, I think it’s worth waiting for Q10. The Z10, while a good device, just does not have enough to compete wit Android and iPhone. Apps are severely lacking and at the end of the day, it is a 1.0 product that needs maturing.