There's much more to worry about ...
... if O2 get an exclusive. To start with, they still seem to think 5MByte for a fiver (ex vat) is a good deal, or 250MByte for £25 (again ex vat), when others are doing 1GByte for £8.
Of course, that's assuming you actually manage to get past the non-sales team and the customer-non-service team to actually persuade them to sell you a contract. To say me experience with them hasn't been positive would be an understatement.
However, having said all that they really really aren't as bad (very bad) as I found Orange AND when I signed up they even sent me a PDF of how to set up a Mac (both OS9 and OS X so that dates it) to use internet access via the phone.
They really aren't that bad as mobile networks go, and it was something of a surprise to find that they actually had some Mac support !