Hello Michel,
Add me to the list of customers who are very disappointed in the fact that there is no support for variables in this product. I am also surprised that you question what might be done with them that cannot be done without. How about something as simple as toggling different scenes when an Insteon button is pressed. Sure, that can be done (and I am currently, begrudgingly doing so) by defining dummy programs for a two bit value each but that is just an ugly way to accomplish something that would be clean and easy with variables.
Or how about something a bit more complicated like assigning a variable a value based on the type of plants in a watering zone along with the time of year. At the end of each day use the weather module to check temperature, humidity and precipitation and formulate a number based on those factors. Subtract that number from the originally assigned number and when you reach zero, schedule watering at the appropriate time. You would need 8 programs to hold a mere 256 bit value (which would not suffice) and a clunky method to actually do the math given the current paradigm. Who knows, you may sell more weather modules (I'd buy one) if we had a better way to program the ISY.
Given it has been nearly 9 months since the last official release and over 4 months since the last beta release and given this does not appear to be a priority I guess it is a pipe dream to think we might get variables anytime in the distant future. Since we cannot seem to get you to commit to a date, can you describe the type of variable support that we may expect if they ever do come available (i.e. size, program and global visibility, statics and not, ability to pass to another program, etc.)
Sorry if this sounded like a rant. That was not my intent but I really feel this little box could be so much more than it currently is if basic things used in the simplest of programs started becoming available.