Image Courtesy Mark Kyrnin
DDR4 may have been finalized but it isn't likely to make it to the PC market for some time. Most desktops will come with at least 4GB of DDR3 memory but there are still some pitfalls to desktop PCs and their memory. To get a better understanding of what impact memory can play in your desktop PCs performance, be sure to check out my Desktop Memory Buyer's Guide.
I believe Mark is correct with his comment about many companies promoting computer ram for new computers that are using new operating systems. However, older computer systems can be revived by simply maxing out the ram memory modules with a decent manufacturer grade.
I of course have my own favorites, but that does not mean their are many companies out their that have high performance memory ram that is durable over the lifetime of the computer system. If you need to upgrade that new computer start with your immediate needs. Computer Ram affects everything so the best place is to start there.