Ubuntu Business Desktop Remix isn't too different from the stock Ubuntu, but it just dumps a bunch of packages not commonly used in the corporate/enterprise world (social networking clients, games, etc) while drops in more business-oriented packages (OpenJDK, Adobe Flash, Canonical Landscape, etc), including VMware View. There isn't anything making up Ubuntu Business Desktop Remix that isn't already available from the Ubuntu Software Center.
Mark says in his blog post, "Before anyone gets all worked up and conspiratorial: everything in the remix is available from the standard Software Centre. Packages out, packages in. No secret sauce for customers only; we’re not creating a RHEL, we already have an enterprise-quality release cadence called LTS and we like it just the way it is. This is a convenience for anyone who wants it. Having a common starting point, or booting straight into a business-oriented image makes it easier for institutional users to evaluate Ubuntu Desktop for their specific needs."
That about sums up this spin that you can look forward to with the Ubuntu 12.04 LTS release in April. Right now there is this image available, but it's 32-bit only, which doesn't make a whole lot of sense in the business world in 2012. Registration is also required to download Ubuntu Business Desktop Remix, which Mark claims is for EULA reasons related to the VMware software.