I read about it a long time ago when it is was still called BizSharp server (See Microsoft werkt in het geheim aan BizSharp Server - article only in Dutch) - but now it is official - here are some article excerpts from Microsoft to bulk up Office Business Intelligence:
The Office PerformancePoint Server 2007, due mid-2007, will provide a set of programs geared at helping knowledge workers to make more informed decisions.
The package, formerly code-named "Biz Sharp," will include a server and tools for analyzing data, creating "scorecards" for measuring corporate health, and planning applications.
Office PerformancePoint Server will have tools for data analysis, corporate scorecards, and planning applications, Levin said. For example, a finanical controller could create a forecast for spending on marketing in the coming year and measure progress periodically.
Office PerformancePoint Server will include the business intelligence software from ProClarity, a company which Microsoft acquired in April. The ProClarity tools, as well as an existing Microsoft program for scorecards, will continue to be sold separately, Levin said.
Also take a look at Ian Tiens posting - Follow-on version to Business Scorecard Manager - see what he writes:
From the publicly available information, you can see that PerformancePoint is going to bring together scorecards and KPIs from BSM05, with analytical assets from the Proclarity acquisition as well as additional functionality from a project codenamed "BizSharp".