What are some games that totally made sense and should've been made (or were rumored/cancelled), but never did get made? Not games you wish you were made per se - but games you expected to be made, but never were.

For me:

• Star Wars Wii - when the Revolution was announced, and then the Wii was revealed, the first game that popped into everyone's heads was "Star Wars Wii!" I remember even watching mock up trailers (like this one from 2006) for it. It made perfect sense - the Wiimote could be used for lightsabers/blasters while the Nunchuck could be used for "The Force." Also both could be used to pilot the X-Wing or Pod Racer.  Not to mention with the built in speakers the Wiimote could have even made the lightsaber humming! It fit so well it was mind boggling.... I was expecting a fully featured Wii exclusive Star Wars game that used these controls. We never got it. We got "The Force Unleashed" which was a meh multiplat, and that's it. I was so disappointed and confused on why we never got that Star Wars Wii. We got the crap Star Wars Kinect though... which was weird.
• Halo DS/Kinect - there were rumors of a Halo DS during the Halo 3 days (see IGN play a demo here). This would have been cool. It would've sold 5 million+ copies so it would be a win for MS and would have been a win for Nintendo because it diversifies the DS' roster and would sell more. On the other hand, I am surprised we never got a Halo for Kinect. The Kinect desperately needed a hardcore gamer killer app title, and what better way to do that than Halo? It's Microsoft's number one franchise. The Wii sold so well because Nintendo not only had Wii Sports, but also launched with Zelda and then had Mario Galaxy and Smash Bros. The fact the number one MS franchise never made it on the Kinect was surprising.
• Banjo Threeie - when MS bought Rare I thought they were doing it to expand their demographics. Rare had the action adventure/platforming franchises Microsoft needed, especially in the early 2000s. So when they announced Banjo Threeie in 2006 it made perfect sense. Instead of getting a fully featured 3D platformer that would rival Tooie we got some stupid car building racer game that predictably flopped. Why even buy Rare if you won't take advantage? It would've been cool to diversify the 360's line up, especially when it practically has no 3D platformers outside Sonic and Crash.
• Final Fantasy VII remake - with the huge successes of OOT/MM remakes, it has been proven people want nostalgic remakes. Final Fantasy VII remake would outsell XIII I bet, or pretty close. However, I believe FFVII remake is probably Square Enix's emergency button when they need to get bailed out. The code for FFVII behind a glass case that says "Break when nearly bankrupt" hahahaha.

Star Wars:  The Clone Wars:  Lightsabre Duels was a Wii exclusive game.  It sounds pretty much like what you were waiting for (motion control lightsabre).  I remember when it came out and being on the fence about purchasing it.  I have a Wii and am a huge Star Wars fan, but I never did pick this one up.  It managed to sell over 1.6 million copies despite average review scores (5.8 on IGN).