Such changes are part and parcel of business life, but the departure of Seiche from HTC will surely raise some eyebrows. As a relatively long term HTC employee and senior figure he will have a deep understanding of both HTC's company philosophy and its operations. Such experience is hard to replace and is potentially valuable to a direct competitor. Moreover, there will inevitably be curiousity about the motivation for the move.
Here's a statement from HTC giving a little more detail on the appointment:
HTC, a global leader in smartphone innovation, has today announced the appointment of Phil Blair as its new Head of EMEA. Phil has been with the company since it launched in EMEA in 2005 and has worked closely with Florian Seiche as co-founder during that time to grow the business to where it is today.
Phil's depth of experience in the smartphone market, intrinsic understanding of mobile products and long-standing relationships with key industry partners put him in a strong position to create new opportunities for the business, taking HTC into its next phase of growth.