TMR Design wrote in post #3963891
I think that 20D owners will appreciate the upgrade to 40D more than 30D owners. They are coming from a small LCD display to a 3" one and they skipped a generation. For them I see it as a more substantial upgrade. Again, I'm not splitting hairs and analyzing this feature for feature. I just know that many 20D owners that chose not to upgrade when a 30D came out will be more likely to move to a 40D and see it as an upgrade based on the better specs and some of the nice features that everyone here has been pointing out. Those features are not in the 20D or 30D so a 20D owner will see and feel more of the change.
If the 3" LCD and a skipped generation are why the 40D seems to you like a more substantial upgrade to a 20D than it is to a 30D, then no wonder you're not hankering for an upgrade. To you with your 30D, the 40D only adds 0.5" and one generation 
I'm not trying to convince you one way or another. You say the 40D isn't a big enough upgrade over the 30D for your wants. Great! That's your right, and nothing wrong with that, and don't let anybody give you lip about your choice. But it's my right to disagree with your assessment of the relative merits of the 20D, 30D, and 40D. If the 40D is a worthy upgrade to the 20D, then it is to the 30D as well (in general; of course this doesn't apply to everybody, as you've demonstrated) or is at the very least very close to being a worthy upgrade. How many generations have elapsed has nothing to do with it. Elapsed time between cameras in my mind is a very odd measurement for worthiness of an upgrade, but to each his own. To me the feature upgrades are much more important than time elapsed, and in the feature area the 40D is almost as much of an upgrade over the 30D as it is over the 20D. Certainly the 40D to 30D gap is much, much bigger than the 30D to 20D gap. If it's a worthy upgrade over the 20D, then at worst it's almost a worthy upgrade to the 30D, certainly not "minor". And consequently, if it's a minor upgrade to the 30D then it is also a minor upgrade to the 20D. That's just how I see it.