Wii U has plenty of great games available right now (especially compared to the competition...both of which, you may or may not have noticed, ALSO had heavily "Coming 2015" conferences at E3). Technically though, there are eShop games being released (Pushmo World for example). Also, even though you "aren't counting it"...Wii Sports Club retail release in July has two games that aren't available digitally yet either (Boxing, Baseball).
Summer is usually pretty slow in general though, so nothing to get too upset about. Mario Kart 8 was a HUGE release less than 3 weeks ago, and the Wii U library is pretty solid already for how far we are into the life cycle. This Fall there are plenty of good games to be had (Hyrule Warriors, Bayonetta, Bayonetta 2, Super Smash Bros., and Captain Toad Treasure Tracker). And 2015 is already going to be AMAZING. It's ALWAYS been this way with Nintendo systems...gaps in the release schedule.
3DS is a little worrisome though...especially since they didn't show a whole lot at E3.
Upcoming Games To Get
Definite: Kirby Star Allies (Switch), Mario Tennis Aces (Switch), Fire Emblem (Switch), Yoshi (Switch), Pokemon (Switch), Kingdom Hearts 3 (PS4), Monster Hunter World (PS4)
Considering: Fe (Switch), Donkey Kong Country Tropical Freeze (Switch), The World Ends With You (Switch), Ys VIII (Switch), Street Fighter V: Arcade Edition (PS4), Kingdom Hearts 2.8 Remix (PS4), The Last Guardian (PS4), Shadow of the Colossus HD (PS4), Anthem (PS4), Shenmue 3 (PS4), WiLD (PS4)
