If Sky offered the same services as BT, I would change to Sky Talk, but they don't - I have my company fax machine running on my home line with the Distinctive Ring service and its own phone number. Sky don't offer this, so I can't change.
So, in March I will be migrating to Be* unless they relent on the price in the meantime. In a poll on the Sky User website, 66% have voted that they will change ISPs when the increases come in.
Home ADSL: Sky Max LLU
Business ADSL: ZeN Office 8000