Keep in mind that all these speculative execution exploits rely on being able to already execute code on the target, they can only read data somewhat slowly, and where the data you want to read is in a 64-bit address space is not easy to find.

The media loves to blow things out of proportion, but all the specexec attacks are really not as big a deal as e.g. remote code execution. In some ways, they are the real-world equivalent of "you can sometimes hear things your neighbours say, with a sensitive microphone and lots of patience."