Microsoft is working on version 2 product (Currently in Beta here) and will likely address the most critical shortcomings, and with the next release (targeted for 2010) should get the product to the classic Microsoft design point.
In the interim, we can still expect that the number of footprints that Hyper-V makes (despite the product’s current maturity level) will be staggering and will turn the volume metrics of the market upside down.
These footprints are likely to penetrate all size class customers. Within the largest customers, many of which have already committed a substantial amount of their infrastructure to VMware solutions, expect use of Hyper-V to be within test, development, and noncritical and lower priority workloads at first.