Today spatstat 1.61-0 ‘Puppy zoomies’ 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):

• Fast kernel estimation on a linear network using 2D kernels.
• Nonparametric maximum likelihood estimation of ‘rho’.
• Extension of Scott’s rule for bandwidth selection.
• Cross-validated bandwidth selection on a linear network.
• More support for character-valued images.
• Random thinning of clumps.
• Bug fixes and minor improvements.