What a long and thought provoking thread... let me add my $0.02 worth

I am a (professional aka commercial!!) web developer, have been using mambo then joomla for years on client sites and have used commercial and gpl extensions and templates along the way. I have used a number of CMS but keep coming back to Joomla - I like it and most of all, I find that clients can easily use it and learn to take control of thier own sites, which I think is Joomla's biggest strength.
I have just started to develop a niche application that I was considering releasing as a joomla extension for 1.5. I am a big fan of joomla and had thought of releasing a 'standard' version for free and a paid-for 'pro' version.
Maybe I need to re-think this? I have been doing a lot of thinking around business models, and while not fixed on one yet, I thought it might add something to this thread to expose my thinking:
To release a component (that will take say 1+ years to develop and test), options are:
a) release the software as gpl and ask for donations. All support free.
PRO: get the max number of users in the early days. Good for beta testing.
CON: probably very low ratio of downloads to donations with big ongoing personal committment to support.
b) release the software free and charge for access to manuals, forums and support, etc.
PRO: maximum number of users/downloaders. easy to 'try and see'.
CONS: personally I find using components like this a pain in the ass! When evaluating components the forum is a good way of evaluating how serious the developer is and what kind of problems people have. Also where do you draw the line? no support for installing the component will alienate a lot of (especially) newbies.
c) release a free version and a paid-for version. All support free.
PRO: attempts to give everyone something they want. versions available for free, more powerful (or maybe just unbranded) version available for a one-off fee
CON: added overhead of maintaining two versions of product. Power-users can easily remove branding themselves therefor not seen as adding value?
c) dont release the software, but provide it as (paid-for) hosted service
PRO: provides on-going, recurring revenues instead of once-off software purchases. No installation or software support required.
CON: additional cost of online sales and time required on end-user support. Doesnt contribute anything to the joomlashpere
d) dont release the software, but provide it as (paid-for) turnkey service
PRO: low risk, software doesnt need as much 'packaging' as 3-rd party components
CON: limited by the amount of time I have to configure and install. Doesnt contribute anything to the joomlashpere
I'd be interested to see other 3rd party component and template developers point of view on the business models. What have I missed here?
Just as a parting shot... could someone explain why you can release a template as non-gpl but not an extension?
Does this mean that I could release an extention as gpl but release the frontend user interface as a paid-for template. This seems pretty horrific to me but might be what we end up with??
Thanks - Apologies for the long post. This seems to be a thread of long posts. Probably shows how fundamental the issue!