While that's true, I just really don't understand why I have to resort to sucks hacks to simply eliminate idling. I am a paying Heroku customer with a CC on file... I just want to give them money to do something properly which I could hack around legitimately.
The fact that this has clearly been brought to their attention before and they have offered no real answers (I'm literally suggesting a checkbox for $10 a month or something that simply keeps my app un-idled) frankly gets me thinking about ulterior motives. I love Heroku, and find their services very valuable, but some of their decisions make very little sense to me, like this, or more recently how they've handled the RapGenius accusations.
I totally agree that hacks to avoid idling when are willing and able to pay is lame. We've actually been working on something very similar to what you describe. Send me an email at adam at heroku dot com and I can give you early access.