Knights of the Old Republic is not that different from normal Star Wars. I mean, even the ship setup is the same.
Good Guys: Ugly craft, except for the Player Ship which is a rugged smuggling craft and is thus somewhat Anti-Heroic, allowing it to be cool.
Bad Guys: Star Destroyers. 'Nuff said.
There's a lot of backstory around that 50 year period between 30 BBY and 20 ABY, and you don't even have to stick your hands into the NJO, Swarm War, and Legacy. Praise the Lord for that. If Bioware had actually wanted to be risky, we wouldn't have played Jedi and the Sith wouldn't have been the main nemesis. Good grief, people know it's Star Wars after somebody pulls a Lightsaber, fires a blaster, or does a Force-Push.
The Force Unleashed isn't a breath of fresh air as much as I'd like. Certainly not as much as Mass Effect or Jade Empire. But it's a start for Star Wars - actually exploring an era of history that is more than history in the Galaxy Far Far Away.
Knights of the Old Republic can never really be touched upon by another series because it's set FOUR THOUSAND years in the past. This is a bad thing. Think about it. You can't really have an in-joke short of "I have a bad feeling about this.", appearances by characters from KotoR is effectively impossible, and even touching on the events of KotoR will jerk you out of immersion - this stuff happened four thousand years ago! Most people couldn't tell you what was happening 100 years ago.
Let's take a mosey down History Lane for a moment. Around 2000 B.C...(BCE if you want to be PC)...well, that's around the dawn of the Chinese Bronze Age, Stonehenge was completed, the Latins (That'd be the ancestors of most of the European races) arrived in the Italian Penninsula...
Gee, I remember reading that about that in my history books...wait, no. KotoR has a massive issue that makes it quite unviable - it's enough alike that it's not new, but it's enough different that it's practically a different galaxy. It looks like another Galaxy in Star Wars that developed on a similar, but slower path. And if too many fans of this appear, then they've got a serious problem - the bridge between the 'Modern' SW Era and KotoR is Four Thousand Freaking Years.
Well, that was a hell of a rant.