Are there any feasible tests planned for testing string theory, or will it always remain a beautiful mathematical proof with no real world evidence?
Ah, a testable theory. Really, you want it all don’t you?
A string theory that makes any sort of prediction at all would be a good start.
[ \snark]
They make predictions! Just because you aren’t good enough to actually make the experiment is your failing. 
Well, if you don’t care about the feasibility of the experiments, at sufficiently high energies/small distances, the string-like nature of fundamental particles ought to become visible; but those distances (around the Planck length) are completely inaccessible as of now, and for the foreseeable future.
Also, string theory is a quantum theory, and includes general relativity as its limit – so if either of those is falsified, strings are out, too.
There’s also the issue of extra dimensions and supersymmetry: both are needed by string theory, so their discovery would at least build some confidence; but, both are also compatible with other theories. But really, that’s more or less always the case: for instance, the perihelion rotation of Mercury is taken as evidence for general relativity; but there exist other theories that predict the same effect, or a sufficiently similar one.
And then, string theories are in a sense ‘dual’ to ordinary quantum field theories (which is why I prefer to think of strings as a framework, in the same sense that quantum field theory is a framework, with, say, quantum electrodynamics being one of its specific applications), and that duality can be exploited to use stringy calculations to make QFT predictions, which can be tested – and actually has been, with the result not being very favorable (this article at Backreaction provides a good discussion). But of course, quantum chromodynamics does actually not quite fulfill the conditions needed for the duality to work well, so there’s always room for discussion…
Wait - is String Theory an actual theory, scientifically? Or is it just an hypothesis?
Yes I think it qualifies as a theory, as it cosnsits of a theoretical framework. I would not call it a hypothesis at all actually as that would suggest it makes clear predictions which at the present time it doesn’t do.
I think people just need to take string theory for what it is: a potentially very powerful theoretical framework, but one that has a number of properties (including it’s own broadness) that has actually made it prove difficult to formulate testable hypotheses from.
Since it’s likely that the Higgs boson is real, I’ve read that this implies that the heavy particles of supersymetry (susy) must also be real. Does susy obviate the need for string theories, or is the issue still how to incorporate gravity into the standard model. Thanks.
Certainly aspects required by string theory are potentially falsifiable. The biggest item on the list is the existence extra small curled up spatial dimensions. Gravity is able to spread through all spatial dimensions, so measurements of gravity effects at very small distances that demonstrate consistency more with multiple small curled up dimensions and that are inconsistent with only three extended spatial dimensions would be consistent with string theory whereas ones that where consistent with three spatial dimensions only would falsify the model. There are experiments in progress that ask that question. (Including ones planned at the LHC.)
Well, not directly, as far as I know. The issue is that the observed value for the Higgs mass, if that’s indeed what’s been observed, lies near a value (about 120 GeV) that would indicate the instability of the vacuum – i.e. we’d live in a so-called ‘false’ vacuum, which, like a radioactive particle, in principle might spontaneously decay to a lower energy state, which would be bad. SUSY is one of the possibilities to make a universe with a light Higgs stable, but so far, it’s not known whether it’s needed (as I said, the observed value is very close to the critical one, and things also depend on the mass of the top quark, so all might be well on its own). This is something one would have to look at more carefully, should the data indeed indicate a ~125 GeV Higgs.
Well, SUSY is an integral part of modern string theories – often also known as super-string theories for that reason --, so evidence for SUSY is therefore at least consistent with string theory.
As for the question of ‘unifying’ gravity and the standard model, however, an interesting model somewhat supported by the data is the asymptotic safety proposal (which isn’t so much a true unification, but an attempt to make things at least consistent), which roughly claims that you can turn gravity into an ordinary quantum field theory after all, the ‘infinities’ that otherwise plague this attempt being merely an artifact of the specific techniques used. Within this framework, a 126 GeV Higgs has been predicted, plus no other new physics up to the Planck scale (I’m not sure about the vacuum instability in this case, however).