It's always difficult for the forum admins to know when to make a switch like increasing image size. It's almost a guessing game as to when is the optimum time to raise that bar. The evolution of personal computers is driving these changes, and it's based on what serves the majority of members best. Whereas there are still some members with smaller displays incapable of showing 1024 pixel images without scrolling, the fact is, most can. Similarly, the number of people with dial-up connections is very small relative to the number of members with high-speed connection.
I had an interesting experience recently that illustrated this perfectly. I wanted a small monitor to put on the corner of my desk. I went to the local Best Buy, and the smallest monitor they had in stock was 17". I was really hoping for 14", but would have settled for 15". They have a 15" monitor listed on their website, but not in the store.
We can't hold back the natural evolution of the forum to accommodate the lowest common denominator. The world is changing, and the capabilities of the average computer/user are increasing. Today's entry-level machines are fully the equal of the high-end machines of just a few years ago, and high-speed internet is available to a significant majority of users.
Even the phone companies had to stop supporting telephones with cranks on them eventually.