I doubt it's high on Microsoft's priority list. Your earlier example shows a saving of a few hundred megabytes out of 8 GB, and RAM is really cheap.
I should point out that in my example, the memory pressure at the time was quite low. Had I pushed the memory pressure higher, the amount of compressed memory would also have been quite a bit higher.
RAM may be cheap, but there are still physical limits that can be hit on any given board or system before you reach the theoretical limits. I'm posting this on a 2009 iMac right now, and it has a maximum RAM configuration of 8GB (which is also how much RAM is installed). No matter how cheap RAM gets, this system can't accommodate any more.
Considering Mavericks was a free upgrade, installing it was like going up to 12GB of RAM or more -- for free. I don't have any metrics in front of me of the useful theoretical maximum compressed memory storage, I can only assume that it's somewhere in the neighbourhood of about (Installed RAM - 1GB)*2 at best (or in my case, 14GB. The 1GB is to ensure space is reserved for wired memory, which can't be swapped or compressed). I suspect it will be a bit less, depending on how compressible your data is (the algorithm used is optimized for a 2:1 compression ratio, however not all pages will be compressible to this degree; my understanding is that if a pair of pages can't be compressed into a single page, the compression routine stops for that pair of pages).
Note that as memory compression sits between the point where the OS identifies that it may need to evict old pages and the point where the pages are physically swapped to disk, the pages written to disk are also compressed (unless they were incompressible in the first place). This will roughly halve the amount of data that needs to be written to swap, meaning that the slowest operations of the paging to disk procedure is roughly halved in time as well.
As Windows machines swap as well, being able to halve the time required to read data from and write data to disk would be a huge boost. Being able to get a few million extra pages without the need to swap is an even bigger performance boost. I'll point out this ArsTechnica article on Apple's Compressed Memory subsystem -- note in particular the second graphic which shows a system under much heavier memory pressure, where a machine with 16GB of RAM has over 8GB compressed, and only 26.5MB (not a typo!) of data swapped to disk. That's a lot of data that didn't need to be written to a page file.
Yaz