The base 15" is more than adequate unless you're doing lots of gaming... which you've said you're not, as you have a console for that.
So, is it worth spending an extra $400 just for a graphics card you won't use and a 0.2GHz-faster processor?
IMO, no.
People who warn you that you "might" use the graphics card in the future are deluding themselves. Unless you plan on going into 3D modelling or something graphics-intensive, the 6490 will be just fine. People are still getting on fine with Powerbook G4s from 2005, which have nowhere near the graphical prowess of the new 15". And people are buying the 13" Pro in droves, even though it has inferior graphics to the 15".
In closing, if you can afford to splurge and get the high-end 15", do it. It's a better machine, without a doubt. But you'd be just as happy with the base model, and you could spend that extra $400 on more RAM and/or an SSD, which will give you way more real-world performance gains than an upgraded graphics card you're not going to take advantage of.
Lastly, if you're thinking about the high-end 15", then consider the 17". I built the 15" the way I'd want it (high-res antiglare display), and that spec is only $150 less than the 17"... at that point, you may as well just pony up a little more for the 17".