No it isn't going to be good either for the workforce or the ordinary public. Same as other privatisations, prices will go up, services will be worsened, and jobs will be slashed and conditions for the workforce attacked.
If it does go through I foresee daily deliveries being abandoned within a couple of years, and replaced with deliveries every other day, Monday to Friday, with no delivery on Saturday. And probably even more infrequently in remote areas.
Prices will likely depend on where the item is going to with higher prices for places outside big cities.
Despite Postcom claiming that the Universal Service regulations requires daily delivery to every UK address at a uniform price, a private company will probably be demanding equal treatment with other private postal companies such as TNT who only do deliveries every other day, Monday-Friday, in the UK and in Holland where they are the national postal carrier.