LoL..this is by far the least expected and exotic topic about cameras!
All the names are horrible, because they are clearly driven by the engineering department. Sure, we can get used to it - but there is almost a forced learning curve - before buying you almost have to understand their naming system, in order to avoid mistakes.
Any naming system that you have to study is not intuitive.
Alpha: suggests either the first or the dominant - but they also have numbers.
D: OK we get it.."digital"..but these cameras will never be mentioned without the "DSRL" designation and all the text about the features will immediately make it clear that it's digital. Again the numbers - they are not chronological. Nor are they consistent with regards to higher# = more features. So you have to learn and understand. Then they have "x" and the "s" sub-category.
Canon: Just like the car-companies they use different model names and systems in different parts of the worlds. At least they try. But what's with the "EOS"..while it may or may not be meaningless, it serves a similarly superfluous as the "D" designation. Aren't all their DSLRs "EOS"?
Olympus: E###..here the engineers have had free reign again. Justlike Canon they start 3-digit number that increase with price/feature set. But when a certain threshold is crossed, the numbers drop again..E3 is "bigger & better" than both E410 and E510..just as D3 is "bigger&better" than D300 and EOS Mark 1 is "bigger&better" than EOS450. The 40D is also an "EOS"?
Sigma...DP1? I'm not even going there.
If there are any saving graces it's that the compacts and super zoom naming conventions are even worse, more meaningless and engineers have been given complete freedom to use as many consonants in a row as they want..lol.
Don't get me wrong - I love engineers. They can do stuff nobody else can. Big important life-changing stuff. But their methodology require them to use a very specific - almost mathematical - notation for their version-control. This doesn't translate very elegantly into consumer information. It's the executives who put them in charge of model-naming that is to blame here...lol...and it's universally acknowledged that it's OK to blame the executives, right?