I disagree with deprecating synchronous XMLHttpRequest: 1) it is not upward compatible & so can break numerous sites. Many websites do not have active development, and framework updates that fix this are even slower to roll out to web apps. Many web app clients would much prefer a sub-optimal experience than a broken website.
2) A better way to approach this might be to respect the async=false setting but have the browser move the script thread to another thread which is blocked until the jax (not ajax anymore) completes. Make the browser do the heavy lifting so scripts remain simple. 3) Loading long chains of on-demand content becomes unnecessarily complex. Example: a config file that specifies URLs for column headers which specify URLs for content requires 3 nested .success handlers. With async=false, one can simple write those sequentially. 4) Have it been considered if jQuery can create a work-around to simulate async=false? If not, do not deprecate, as there will be even more browser-specific code splintering. 5) When data loads slowly, many sites will show a "please wait" view anyway, which disables useful interactions, so how much value does this deprecation add to usability? 6) Do you really want script writers to deal with scroll events while an ajax is outstanding? That seems to be beyond the ability of a plug-in to handle in the general case. async=false really simplifies some tasks. --Gregg Tracton, Chapel Hill, NC, USA