1280x1024? Do you have any data for that? 1366x768 would strike me as the much more likely resolution. The "normal" users I know are split into two groups - those with newish cheap 15" laptops, which are all 1366x768, or those with ancient desktops at 1024x768, or worse, 800x600 because they stumbled on the resolution setting and used it as a way to make things bigger.
Don't say this is the user's fault though. People with weak eyesight NEED to get stuff bigger and because of tons legacy software even Windows 7 can't really help you with scaling. Scaling the resolution is still the only really viable option for these people.
In fact, Apple's way of scaling by internally doubling the resolution on retina displays is the most useful way of scaling I've seen so far. It gives you an -almost- crisp image for 3 different scaled settings and one perfectly crisp image for the retina resolution.
