Hi all,
I bought my t2i end of June and I've had no problems.
I know there have been one or several firmware updates since then, should I do it?
Have you and why?
The only firmware I am aware of since then is to v.1.08. Can't tell you whether you should do it, but Magic Lantern will work with v.1.08. There are a bunch of threads on this if you need more information on what Magic Lantern does/will do with the T2i.
The update was for for certain macro lenses that the T2 didn't want to recognize. If your camera's playing nice with the lenses you own, you don't need to.
Unless you want to use ML, as noted above. However, ML is still in pre-beta testing so use at your own risk.