I'm going to step into the "extra cost" fray. My understanding is that there will be a period of time included in the cost of the software and that all historic buyers will get that. (6 months?) Beyond that it will be an annual fee which, from what I have been quoted, is very reasonable. (I'll leave it to the RexWireless guys to state it officialy; I'm also a beta tester so I've had a few phonecalls with them.)
My view is that some annual fee is essential. Some of us are really relying on this program to keep us organised at work. If the revenue model doesn't fly, Rexwireless won't be around for the long run. Given that Blackberries are constantly changing (and that as good as TodoMatrix is, there will also be more improvements to the program even for current OS use), it's very much in the interest of everyone that they survive.
No, I'm not paid to say this; I'm a paying customer. But I can tell you that these guys are taking their product and its potential future very seriously. Kind of reminds me of... RIM.
Just my $0.02 of course.