The SMT-LIB benchmark repository is now hosted on the StarExec service.
In the future, it will be possible to download the benchmarks directly from this page too. Until then, you can access a copy of the current repository by going to the StarExec web site directly.
Several releases of the repository are available in the following StarExec space:

root / SMT / SMT-LIB benchmarks /
Each release is stored in a space named with a date of the form YYYY-MM-DD. The current release is the one with the latest date.
To access the repository, go to StarExec and click on "Spaces" (top right), "Explore". Then select (left) the space "SMT/SMT-LIB benchmarks", the version you want, and the logic. In "advanced actions", you can choose to download the benchmarks. No StarExec account is necessary.

Note: For bulk downloads, zip archives containing all sections of the latest release of the repository (2015-06-01) are also available here.