According to the AMD Spec, require() should not take a configuration as part of its argument.
While there is no specification for how to configure a load, the common configuration is defined. By convention though, it seems RequireJS uses require.config() to pass the configuration and the dojo/loader already exposes it as require.config() as well.
Since it isn't required to be AMD compliant, I suggest we drop it, as it makes the API confusing and puts extra run-time code to try to disambiguate the call signatures.