The STACS 2012 accepted papers are out. STACS is in Paris and starts on February 29.
The most noteworthy article for my taste, at first glance, is the 13/9-approximation for Graphic TSP by Marcin Mucha, available here. (In some sense this is old news: the paper will be presented at STACS, but was published on Arxiv in August.) They improve the analysis of the Moemke-Svensson paper from last Spring (presented last month at FOCS; was published on Arxiv in April).
Here's a quote: We present an improved analysis of the cost of the circulation used in the construction of the TSP tour/path. [...] The circulation used [by Moemke and Svensson] consists of two parts: the ”core” part based on an extreme optimal solution to the Held-Karp relaxation of TSP, and the ”correction” part that adds enough flow to the core part to make it feasible. We improve bounds on costs of both part; in particular we show that the second part is in a sense free. As for the first part, similarly to the original proof of Moemke and Svensson, our proof exploits its knapsack-like structure. However, we use the 2-dimensional knapsack problem in our analysis, instead of the standard knapsack problem.