Xbox 360 new kernel 2.0.14717 is coming, do not update if you use the jailbreak item
Microsoft are in the process of releasing an update for the 360 (staggered across regions as usual) with no real improvements and early reports are that it might be preventing the reset glitch hack (RGH) which was released last year allowing effectively every 360 released to run homebrew and hack the dashboard to do things like region free, hard drive launching, USB launching and much more (the previous hack with similar abilities known as the JTAG hack was blocked a couple of years back).
To this end if you were waiting around before gathering the gear to RGH your console or otherwise in possession of one that can use updates (dual NAND or something) do not update.
No hard word on anything DVD hack related (a hack method Microsoft were also taking far more seriously in the last year or so) but again you are advised to hold off until more is known as along with the RGH Microsoft's current counter for DVD hacks was defeated around the same time with the hacked firmware known as LT+ 3.0.
As usual this will only worry people that use xbox live or manually update at first as it takes a few weeks at least for games to start carrying the update (the new Mass effect most likely will not have it but we would not be that surprised to see Ninja Gaiden 3 sporting it and we would be quite surprised if Prototype 2 did not carry it) and even then there should be ways around it.