1) There is a reducted price when you own a previous version: http://www.adobe.com/products/photoshop/buying-guide-upgrades.html but there does not seem to be further reduction if you own the latest one. This might or might not change for CS6.
2) In the past there was a "grace period" that let you update freely to the newest if you purchased the old version just before or after the official announcement of the newest one and before the shipping of the new version ,but a contact to customer service was needed. No official time as for the lenght of that grace period. We don't know if there will be one for CS6.
3) The current standalone version of Photoshop is 5.1, but it is the same in functionnality as 5.0.4. But normally, only 5.1 should be in the stores.
4) The next version should be released around April/May, if the 12 months release dates announced in the past are true. If you own CS2, you may be able to upgrade to CS5.5 during the grace period, and might be eligible for a free update to CS6. According to what has been announced so far, for a regular upgrade to CS6, only CS3 and up are eligible.
Lots of may or might, but we are customers, don't know what the plans are, and just see a pattern from previous releases, which does not mean that it will continue that way.
You asked a lot of questions, but you are missing the most critical one: Will you be able to actually upgrade your US version with an upgrade bought in your country? And since the answer is "No" due to serial numbers being region specific (at least that is how it currently is), none of your other questions may actually have any relevance anymore - unless you plan other trips to the US or can find ways of getting qualifying US upgrades, you won't be able to get it working and will be stuck with CS5/ CS5.5.
Hi Mylenium, they are all US versions.
Will you be able to actually upgrade your US version with an upgrade bought in your country? And since the answer is "No" due to serial numbers being region specific (at least that is how it currently is),
I thought serial numbers were language specific, not region specific.
I´m from Mexico, and here they sell the US version, in both, elglish and spanish.
OK but as I understand it you cannot install an English language version using a Spanish version serial number.
I think so John, but it will be only the english version.
CS5 English, US version, same with the upgrade.
PECourtejoie has already mentioned the "grace period," and that is the way to go. CS6 will be announced in April and will be available in May; the "grace period" will be short, only a matter of weeks, so you'll have to time your trip accordingly. But if you buy Photoshop CS5, or an upgrade to CS5 during that time you will be able to get CS6 free-of-charge once it's released, although you will have to contact Adobe's Customer Service with proof of purchase etc to do so.