Please correct me if there is a single file download to run counterparty, i.e. the wallet software.
There isn't. But as I understand developers could package node-webkit version of counterwallet quite trivially. Such a build could come from anyone really but coming from main counterparty team would be best.
I think it would be a positive thing in relation to the time it would take. People can have a strong interest to a native app on their desktop- especially electrum like lightweight clients. more than visiting website, it can feel more secure or local to them (even if the app is essentially browser window in a form) Counterparty can then market a lightweight win/osx/linux wallet being available.
Yes, this what is plan. First step is to make a Chrome App, this will be the lightweight client. Because in fact lightweight wallet and web wallet are same thing (the only difference is the UI hosted on server or locally). After that for heavy wallet we have a bunch of work on Counterblockd to make it installable on every computer (the ideal is to have no more dependencies than counterpartyd).
The urgency for now I think it's to have an heavy wallet. For that I really need to find time to work on BoottleXCP. I need one or two days to update it. I hope this week-end if I finish "My bets" pages before. After that I need also 3 or 4 days to make BoottleXCP light with pyrpcwallet. But is less urgent because for light wallet there is CW.
Is there any update here? I think a node-webkit build of CounterWallet like CarbonWallet would be attractive to some users (plus you can market as having native win/osx/linux lightweight wallets). I tried to build myself unsuccessfully, but I think for someone who has knowledge of the project it should be easy right?