Bump to 1.7.N.
* Implement the method discussed here
to try to preserve the jailbreak through the 5.3.0 update. See the post in question, and the Bridge section in the first post for more details.
Basically, make sure you install (successfully) the bridge *before* the official update.
The usual warnings still apply: 5.3.0 is still a huge mess for the dev community. This is just a somewhat sneaky workaround. For now, new devices shipped on 5.3.0 won't be able to be JailBroken...