I hope they will also work on speeding it up a bit. I needed to go through 25-30 MB SAML metadata dumps, and an xml-rs pull parser took 3x more time than the equivalent in Python (using libxml2 internally, I think.) I rewrote it all with quick-xml and got a 7-8x speedup over Python, i.e., at least 20x over xml-rs.

Python ElementTree uses Expat, only lxml uses libxml2. Right now, I'm working on SIMD acceleration in my not yet released, GPL-licensed fork of libxml2. If you have lots of character data or large attribute values like in SVG, you will see tremendous speed improvements (gigabytes per second). Unfortunately, this is unlikely to make it into web browsers.