I know it's weird saying that the ISU game is bigger than the OU or WVU games, but at this point in the season and with what's on the line, it's true, relative to where we were and what was on the line in those other 2 games.
Let's look at what was on the line had we lost to OU: At that point, we would have been 2-1 in conference play and still in complete control of our own destiny insofar as reaching the conference championship game.
Now let's look at what was on the line when we actually lost to WVU: We fell to 3-2 in conference play. Winning that game would've been amazing for our conference crown chances, as it would have all but assured us an appearance in the CCG. But at that point, with OU and WVU both already having a conference loss and still having yet to play each other, our hopes of appearing in the CCG remained very much alive, and still do.
Now, what's on the line with the game this weekend? The OP sums it up nicely. If we win, we have a very good shot of playing for the conference title. If we lose, we are eliminated. Plain and simple. This is the biggest game of our season to date.