Not saying it's a bad deal. Just saying for me it's way out of the ball park in terms of weight. I use my laptops as portable computers.
I think you are comparing apples to oranges.
One is a big, heavy, expensive (but potentially still good value) desktop replacement. The other is a lightweight, compact, portable laptop with the same CPU power.
Good to have choices though.
I'd like to have the choice of getting the 15" MBP without the toolbar and with only integrated graphics, because that's what would suit the Apps I use (pro audio apps that are CPU intensive but not video intensive.
I'd really love the 13" model with a quad i7 for increased mobility moving between work and home every day.