Whats funny is people hardly ever talk about Sehwag's backlift, its nearly as high as Lara's, definitely much higher than Tendulkars.
Ravi Shastri also mentioned that he uses one of the lightest bats in the Indian team around 2.7.
What was Lara's bat weight like? Id think it was pretty damn light.
Anyhow the very light bat certainly aids tremendously with the high bat speed Sehwag produces and also helps a lot with the horizontal bat shots such as the cut and sweep.
Tendulkar has always been an all round player but certainly didnt use the horizontal bat shots to the same effect as Lara, I recall Sachin actually punching even the shorter deliveries off the backfoot back down the ground with a straight bat. The lower backlift coupled with an extremely heavy bat is perfect for punching the ball straight and driving in general.
Anyhow Sehwag and Lara's high backlift certainly aids their free flowing strokeplay and its extremely fun to watch.
I think apart from Tendulkar who uses a heavy bat, most stroke players tend to really pick the bat up, Ponting is another one. Viv was different though and had a medium to low backlift, but he was perhaps one of the strongest hitters of all time, freakishly strong really. Yuvaraj really picks the bat up aswell.
I see too much of coaches telling kids to lower their backlifts when really it should be encouraged if it comes naturally to you, especially in the modern cricket age.