If you look closely at /usr/lib you can see that some lib<whatever>.so.2 files are just symlinks to some other version of the library.
In the case of libssl.so.2, I find that the openssl096b package, when examined with Midnight Commander, does not contain libssl.so.2, but rather libssl.so.0.9.6b. Perhaps a symlink would be created on install. I already have libssl.so.0.9.6 and libssl.so.0.9.7.
The existence of a lib<whatever>.so.<number> file is sometimes ignored by urpmi. It complains that it needs this file, which you already have. RPM is one of those nice ideas that doesn't always work. The solution sometimes is to get the tarball (tar.gz) version of what you are trying to install.