I have never calibrated a monitor, wouldn't know what to expect, and I only game and browse the internet. I have a U2410 also but have never had any obvious color issues (have had some mild saturation issues, but they are rare), and would consider myself to be somewhat sensitive to them. I did a bit of contrast and brightness adjusting initally, a tiny bit with the color, everything looks about as good as on my old CRT and a couple TV's, colorwise at least, nothing that I think most people would notice without placing different units next to each other. I have yet to see any complaints about things like skin tones from actual users who aren't looking to do color-critical work on the U2410. Only complaints I have seen are over lighting uniformity (which can lead to perceived color uniformity issues), and a little bit over black levels and backlight bleeding, and even these issues shouldn't show up unless you look for them on all black or all white screens in a completely dark room.
Let us know how it turns out. I haven't seen any post-calibration comments about this monitor except in reviews, and in those cases they usually just compare color charts. I'm tempted to grab a colorimeter off ebay for cheap and calibrate mine just to see what happens. For those of us who just game though, I don't think we have much need for it outside of a casual interest.