I think it's fruitless to try to compare players across eras. No one knows how Bradman would've performed in the 1990s and no one knows how Tendulkar would've performed in the 1930s. And no one, for sure, knows how Sehwag would've performed against "all time greats." The question is, ultimately, irrelevant. What does matter is, Sehwag, today, is pretty darned awesome and can easily be considered a great among those players playing today. As was mentioned by one of the players at the end of the match (Tendulkar, I think), Sehwag is a one of a kind player out there today and he's very glad that Sehwag plays for India. As am I.
Frankly, I wouldn't want any other opener in the world today opening for India in place of Sehwag. Not Smith, not Hayden. He may not always be among the runs and some will argue that his test average flatters him, but it cannot be denied that he has a very useful ability to just score runs out of nowhere. Not the kind of player who can be easily tied down. And while that does get him out on plenty of occasions, when he does fire, it's oh so beautiful and helpful. India has plenty of great batsmen to play "responsible roles" - guys like Dravid, Tendulkar, Laxman are all capable of playing an anchor-style role. In that sense, it's an absolute blessing that we have a guy like Sehwag who can do something different. I absolutely, 100%, agree with the decision to give him the MoM in today's game because it was truly his rocker of an innings that set things up for Gambhir, Tendulkar and Yuvraj to finish it up today.