The more I see of it and poke around in it, the more strongly I believe that SBS is a total turd that shouldn't be inflicted on anyone. Probably not entirely realistic or fair given the steep discounts it allows with some of the bundled MS apps and included CALs, but that's my opinion on it.
Having said that, if there's no business need to upgrade to Server 2012 Standard, you can still get some extra functionality and features out of upgrading to SBS 2011, and there are worse things than running an old platform. Hell, we still run Exchange 2003 (in a very large environment), and though it's getting very long in the tooth and difficult to deal with, by the time we finally replace it, it will have provided 10 years of service for a single upfront licensing fee, which is obviously appealing to the cost-conscious side of the business.
Remember that business needs drive IT, and not the other way around, so if you can meet the business needs for a few more years by spending a few (several?) hundred dollars on an upgrade to SBS, rather than thousands on replacing it with Server 2012 Standard, you probably should - seems to me like the responsible, ethical decision, even if SBS does make my skin crawl as a techie.