All time Alpha user- Should I get Nikon D4?

I have never used Nikon or Canon before. I only have used Sony's camera starting from HX100V. Now I have HX100V, A55, A77, and NEX-7. I am not pro at all, but lately I have been thinking about blow my money on high end camera. I am looking into getting Nikon D4. I like its burst and very large buffer. I really don't mind paying for its high cost and but new set of lens. However, I am huge fan of Alpha series. I always liked what Sony have done to their cameras. Do you think I am going to be happy D4? I really would regret if D4 ends up in closet and I continue to use my A77 LOL Would you wait for official spec announcement of A88 and A99? or Would you just go ahead and pull trigger on D4?

Thanks