i think aros could be a success, not a windows beater but deffinitly a success. look at how many people want an alternate os and tried several, but couldnt use them because they were too complex like linux, or pretty useless (pretty but useless) like bunches of others. most of the alternate os's started out with a tiny fan base, maybe a dozen people or so. aros is starting out with quite a bit. lots of people trying it out, developing etc.
also consider that most os freindly apps in open source and public domain should port over very easily as well as many linux/unix stuff needing relatively minor work to port.