This is a summary of recent technology and site configuration changes that affect the English Wikipedia. Note that some changes described here have not yet gone live as of press time; the English Wikipedia is currently running version 1.28.0-wmf.20 (3b2ecce), and changes to the software with a version number higher than that will not yet be active. Configuration changes and changes to interface messages, however, become active immediately.
The magic words for namespaces and pagenames can now be used as parser functions to return the desired namespace or normalized title/title part for a given title. (r46662, bug 8249)
GeSHi has been upgraded to r1402, providing syntax highlighting for additional languages. (r46666, bug 10967)
Import and export functionality have been added to the API. (r46815, bug 17007)
Revision and log suppression (RevisionDelete) is now enabled for oversighters, so that edit summaries and log entries can be hidden but are not completely purged from the database. This feature can be used in cases of vandalism, spam, and other abusive edits and actions.
The Wikimedia Foundation has purchased 36 new application servers (with 8 cores at 2.5 GHz each). So far, 9 of the servers have been installed, making the page load on Wikipedia much quicker and helping alleviate site slow downs which have occurred at peak times when the servers had hit a CPU wall. With the new servers installed, the AJAX suggestions for searches have been re-enabled. 
Internationalisation has been continuing as normal; help is always appreciated! See mw:Localisation statistics for how complete the translations of languages you know are, and post any updates to bugzilla or use Betawiki.