Apple's iPhone was the first phone I'm aware of to completely disallow pre-installed cellular-company software. You can choose to download the AT&T app, for example, but AT&T gets no software on an iPhone out of the box.
The recent CarrierIQ scandal highlights the benefits of this separation. I cannot stress enough how much a keystroke logger built into the OS for carriers is very bad news.
I expect that carriers are not leaders in developing and maintaining software that helps create the best experience for users. It is not their expertise.
I'm flabbergasted at this CarrierIQ news and I am glad to be using an iPhone!
UPDATE: Apple has a very limited form of CarrierIQ installed. You can turn it off under Settings, General, About, Diagnostics & Usage, Don't Send. You can also see what data is gathred under Diagnostics & Usage.
Apple has promised to not use any form of CarrierIQ in the future in any case.
I have seen reports that Carriers (or is it the OEMs?) are not following Google's recommendations regarding settings related to security. It is at an NCSU website