It was just freshened up for 05. There will most likely be some BNG for '06 and Yamaha's 50th anniversary. You'll see some more substantial tweaks in '07. That bike is so god damn good right now though, 99% of people will never need anything more then what it currently is. I'm sure undertail exhausts will go the way of neon graphics too in a few years.
Undertails do "clean up" the look of the bike by giving it perfect symmetry, but undertails just add weight in the wrong place. You want weight down low, like the Gixxer 1000 exhaust, not at the highest point on the bike ala 636/6RR or 600RR. And many may say the K5 1000 exhaust is ugly, but its design is all about lowering the center of gravity of the bike. I really wouldnt be surprised if more companys start moving to triangular exhausts mounted nice and low. Low weight, with adequate ground clearance.
I didn't mean to harp on the undertail exhaust, just wondering when it was going to get a refreshed look. Just seems to be the same look with different graphics unlike the 636/gsx6, etc. Just meaning for healthy conversation. I'll be getting a sv650 when the finances are in line.