Installing on a given Linux distro couldn't be easier, a quick couple of clicks using a package manager and you've got whatever you want - if it's in your distro's repositories. That I see as a problem. It should not be the distro developer's responsibility to make a program work on its distro, it should be the program developer's responsibility to make his program work on a distro. If the Firefox devs, for example, were inundated with 5000 emails about it not working on Ubuntu, they'd either quickly fix the problem or quickly lose 5000 users, thus freeing the Ubuntu devs to focus on their OS, not other people's software. Granted, there is other people’s software in the Ubuntu OS, but…
So, what is needed is a central Linux Software Repository, used by all distros, where software developers could upload their software, and users could rate it, download it and/or request/buy it on cd. The repository would know what distros the software works with and users would know this too from their distro’s GUI (package manager). Users could request any software for their distro if it wasn’t already available – though it would be up to the software devs to do this – or some other kind, knowledgeable soul(s) to do it for the devs, perhaps even the distro devs. Users could flag uploaded programs as malicious and such software devs would be banned from uploading again. The Linux Repository would also be a store, with commercial software for any users that would like such software. The software would be back in the hands of its developers and all would be right with the universe again.
There is only one entity that I know of that might be able to achieve this though, and it's not Ubuntu, but Ubuntu could fork over some resources to The Linux Foundation for this, and encourage other distro’s to do the same. What do you think?
Disclaimer: I’m certainly not a Linux expert, but I don’t see any reason why this couldn’t work other than a lack of support for it to work. I mean, this repository would have to be quite “intelligent” and would be a considerable amount of work just to pull it together, not to mention changing package managers to work with this repository and getting it to accept commercial transactions and requests for cd’s of software and such – it’s a massive undertaking, no doubt. But, is it possible and is it worth it?