I've read (and tend to agree based on experience but without the actual data) that modern digital sensors have reached a point that they outresolve most film. Many people tend to forget that film grain is comparable to pixel count in the context of resolution/sharpness. I recently purchased a Nikon D7100 which is a 1.5 crop factor sensor at 24MP. I've had it all of three days now and have shot about 500 frames with it. But I've had the opportunity (without intentional testing) to compare results of shots of the exact same subject taken at different settings as the lighting significantly changed.
This morning on my way to work, I stopped by a local pond and shot some bird photos. I was shooting the D7100 w/300mm plus 1.4x TC so collectively a 420mm lens. If you pay attention to crop factors that's 630mm effective plus the camera has a function to shoot in 1.3 crop so effectively like shooting a 14MP full frame sensor with an 820mm lens. Using the ages old strategy of keeping a minimum shutter speed of 1/focal length, I started the shoot at 1/800ss and as light increased moved progressively to 1/1250, 1/1600, and ultimately 1/2000. Wide open aperture at 5.6 the entire time and when I got to 1/1600 I also began to tweak my ISO a bit.
I do not have real steady hands but historically the conventional wisdom of using ss = 1/focal length has worked for me. But when I look at my results from this AM (admittedly I am a pixel peeper), the frames shot at 1/800 are unacceptably blurry, 1/1250 would be OK for small prints, 1/1600 are finally what I consider sharp. The ones shot at 1/2000 are so crisp that without sharpening they would display well on the web at the native resolution of the image. I assume the missing AA filter in the 7100 accounts for that last bit of improvement.
But the entire point of my post is that the conventional wisdom of ss = 1/focal length does not appear to do it any more for the high rez sensors that are now available.
Another of the conventional wisdoms that I would challenge is the ages old assertion that one can't go wrong investing in glass. While I agree that holds in most cases, I believe that camera bodies nowadays can make so much difference that they may provide more bang for the buck. Depending on what type of subjects one shoots and on skill level, less noise and higher resolution images may be more advantageous than high end glass.
Revisiting old paradigms may prove beneficial both to the quality of one's photography as well as to the bank account