Top 100 Firms in 2012 Also See Big Jump in Demand for Attest Services, Cash-Flow Forecasting and Management Accounting Today reports in its latest iteration of Top 100 Accounting Firms that the top two fastest-growing niches in accounting services are now international tax services and state and local tax services, edging out business valuation, last year’s fastest-growing niche.   Danielle Lee reports (free registration required):