Should I hold off on purchasing the Xperia Tablet Z?

I'm in a real predicament right now.
Straight to the point: I don't know if I should go with the Sony Xperia Tablet Z or wait to see if Sony will be releasing a new tablet later this year.
Seeing as how the Snapdragon 800 and 600 are more or less the standard in processors now, would it make much of a difference getting the Z Tablet with the S4 Snapdragon?

I'm not incredibly adept in my understanding of processors and their overall effect on the product. But I'd like to get some input from the community. I do for sure want a Sony Tablet though.
P.S. This will be my first tablet as I have been waiting for a good motive and the right time to make the jump. So I want to make sure the Z warrants my change to the slate. I want the tablet to still be comparable to others in 18 months (is that even possible?).

So I want to know 2 things.
Do you think Sony will release another tablet anytime soon?
Are the specs of this tablet worth the commitment?