800k Wii U consoles between March and September is too low, that's less than 30k on average. Maybe March to May won't be much higher, but June-September should be higher.
Mario Kart 8 will probably have a bigger impact (percentage) than Titanfall + inofficial X1 price cut.
We can't say much about the holiday season, it will depend on E3 announcements and price cuts of both consoles.