It's nonsense and exactly what branding is for, a linux kernel is a commodity with a price near zero, in order to differentiate a commodity product you need to brand it.
Branding is about perceived differences and having the consumer identify with your brand. Not that you are repackaging the same goods as your competitor, anyone who knows that is already lost to your campaign and as such is irrelevant.
Surprise surprise... the newer kernel has more performance optimizations and is somewhat faster/featureful.
There are a few new features - see here for more on one of the data integrity ones:
http://www.c0t0d0s0.org/archives/6919-About-this-data-integr...
1. Encourage customers to adopt this kernel to run Oracle workloads. Saying it's the only "recommended" kernel for Oracle software helps greatly. Oh and it's 75% faster.
"The Unbreakable Enterprise Kernel is now the only Linux kernel Oracle recommends for use with Oracle software."
2. Still "support" Red Hat's older kernel for other ISV workloads (really Red Hat is supporting it anyway).
"Oracle Linux continues to include Oracle’s existing Red Hat Compatible Kernel. Customers can choose to run the Red Hat Compatible Kernel if they prefer strict Red Hat compatibility over a system optimized to run Oracle and other enterprise software."
Unbreakable Linux didn't really present any huge advantages before. Now it does. Why wouldn't you choose it now?