If you have a conviction, spent or current then you need a Visa, as you cant travel on
the Visa Waver. This has been the case for many years.

The change from October this year are a change to the Passports, you will need a new
Biometric passport. If you do not have one of these new passports you will then need
to get a Visa as well

The UK will not be ready to issue these for another year or so, hence the need to renew
your passport now, or you will have to get a Visa

Hope this helps