I feel as if the trend in type size for body text is shifting towards larger text. I just see it happening all over the internet on websites I visit. A few years ago, 10-12 pt used to be the norm, but now I often see 14pt being used.
Monitors have a much higher resolution these days. When a few years back, 1024x768 on 17″ (75dpi) was the norm, nowadays 1680x1050 on 22″ (90dpi) or 1920x1200 on 24″ (~94dpi) are mainstream. (I'm even at 125dpi with 1280x800 on 12.1″)
No wonder a larger font size is needed to get the same experience as a few years ago. I find myself scaling the font when reading longer texts, because too many fonts are just too small.
Decreased readability is a subtle byproduct of the increasing number of monitors, as well.
I have three monitors, and because of how they're arranged, the distance from my chair to the monitors is 3-4" back from where my single monitor used to be. 3-4" makes a noticeable difference.
Before that, I had a huge CRT monitor, which sat closer to me by necessity because of the tube size. Without the tubes, we push monitors back to free up desk space. This also increases the distance from your eyes to the monitor.
Lastly, there's the issue of laptops versus desktops. What is comfortable for me to read on a laptop sometimes looks microscopic on a desktop. If you design web sites on a laptop, make sure you check the look on a desktop.
I'm beginning to see the opposite. I find myself zooming in most web pages, because otherwise I can't read comfortably. I had to zoom thrice the page with the article in order to read it (I have a 1920x1200 24" monitor).
