1.11.3 contains various applicable bugfixes encountered while working on the 2.x branch, notably a GeoIP database compatibility issue (they added a new country code for South Sudan, but there's no associated binary version increment to indicate the library incompatibility...). It also notably deprecates the SPF (and thus SPF+) RR-types, which will be removed in 2.x. For those not following the news on these, basically it's always been better just to use TXT for this, and now there are some conclusive RFCs published that deprecate implementing/using the Type-99 SPF RR at all anymore.
In related news, 2.0.0 is nearing completion. Most of the remaining work is just documentation updates, testsuite updates, and heavy-duty analysis/review of all the new code for ugly bugs. There's a little more work to do on systemd compatibility, but honestly that could wait for a future release if necessary. The 2.x branch on github is probably a fair representation of what 2.0.0 will look like code-wise, lack of good documentation aside (although most of the significant changes are already covered in the NEWS file there), if anyone wants to start playing with it early.
2.0.0 is long overdue at this point and I've failed many past predictions at release dates, but hopefully we're out of the woods now and it will happen within the next several weeks.