it looks like WA team is really lazy, look at the iOS version! iOS7 was released to developers months ago and still, it has the iOS6 interface lol.
I'm afraid the same is gonna happens here for the Dalvik/ART switch.
hope I'm wrong ofc.
I'll reiterate that this is not the fault of the WhatsApp application. The ART verifier was blocking the installation of this app, but we are going to fix ART to address this issue. I'll update this bug when the fix is in AOSP.
I think is not a lib problem:
Version 2.10.768(no libs in apk) installs fine but not work, "software too old error"