2 things from last year, on solution paths of SVMs and related methods (parametric quadratic programs):
B. Gärtner, J. Giesen and M. Jaggi.
An Exponential Lower Bound on the Complexity of Regularization Paths.
arXiv:0903.4817 [cs.LG]
B. Gärtner, J. Giesen, M. Jaggi and T. Welsch.
A Combinatorial Algorithm to Compute Regularization Paths.
arXiv:0903.4856 [cs.LG]