The only time it gets wierd with the cartridges is sometimes how they 'bond' them together and at times fuse the batteries too. But if you're comfortable with disassembly and such, batteries are so easy and plentiful when you don't get them from the manufacturer.
Yeah that would be my fear is that is going to be the new norm -- Sonic welding a carrier closed that cannot be opened without breaking it in order to make you buy OEM. Worst case you can buy ones in carriers from places like
www.upsbatterycenter.ca (+Shipping or Amazon with the shipping built in) but it eats into the discount.
Reminds me a lot of printer inks. Putting in chips, sensors etc just to force you to pay extreme markup.
The few I have done so far that have carriers were fortunately just screwed together.
APC has a Lithium Ion line which should help with this as they cant overcharge the hell out of them like they do the SLAs and the batteries will last quite a bit longer. Expensive at the moment though.
edit: I am a terrible spelller