Today spatstat 1.51-0 ‘Poetic Licence’ has been uploaded to CRAN where Windows and OSX binaries are also available. You can also download it from the github repository. The main changes are (full release notes here):

• New fast algorithm for kernel smoothing on a linear network.
• Leverage and influence diagnostics extended to Poisson/Gibbs models fitted by logistic composite likelihood.
• Two-stage Monte Carlo test.
• Dirichlet/Voronoi tessellation on a linear network.
• Thinning of point patterns on a linear network.
• More support for functions and tessellations on a linear network.
• Improvements and bug fixes.