I personally think the current lineup of Vita games is already on par with the 3DS games in spite of not even being released yet. Lumines, ModNation (I liked it., shuddap :P), Uncharted, and a slew of Downloadable games is on par with the 'great' games the 3DS has. Excluding ports, what does 3DS have? Mariokart, super mario 3D Land, Resident Evil Revelations, Nano Assault, and Pilotwings? in a year? Vita has Uncharted, Lumines, Wipeout, Hot shots Golf, and Touch My Katamari?
Once we factor in downloads, 3DS has Pushmo and Mutant Mudds (whatever that is), but Vita has gravity Rush, Super Stardust Delta, Motorstorm RC, and Escape Plan. If you factor in Ports, that means the 3DS also has Zelda Star Fox, Street Fighter, Skylanders, and some others, whereas Vita has Rayman, BlazBlue, Fifa, MArvel vs Capcom, and more.
I'd say this is damn impressive, and I'd be inclined to add Little Deviants and ModNation Racers to that list.
nintendo is currently ahead, but Vita isn't even officially released yet.
Yes, it's worth it. ESPECIALLY if you get a decent sized card and download PSP games like I plan on doing with Disgaea and a few other gems that I could never find on PSP. (thinking about getting the Persona games, too, but they are pretty expensive and to be honest I'm not sure if their style fits me well.)
My Console Library:
PS5, Switch, XSX
PS4, PS3, PS2, PS1, WiiU, Wii, GCN, N64 SNES, XBO, 360
3DS, DS, GBA, Vita, PSP, Android