Not quite. PCIe is just the bus transport protocol. The PCIe SSDs still need a protocol to describe data operations to and from the OS to the Drive. Currently, they use the same protocols as those designed for HDDs, and those protocols make a lot of tradeoffs and assumptions about disk access time. The reason NVMe is exciting is that it is a brand new data protocol, designed with low latency SSD style storage in mind. We're already seeing speeds much higher than existing PCIe SSDs can manage (3+ GB/s!)