As fun as it is to criticize Microsoft, its DW/BI toolsetnotably SQL Server 2005contains the features necessary to build a complete DW/BI system. The tools are relatively easy to use, and will scale from small operations like the hypothetical Adventure Works Cycles to large enterprises with significant data volumes . The smaller implementations can rely heavily on wizards, and not worry too much about all the technical details. Large systems will use the wizards to get started, but will need to dig far deeper into the products.
Microsoft is delivering the technology you need, but you are the ones who will put that technology to use. If you can maintain your focus on the needs of the business users and on adding business value, you should be able to build a great DW/BI system.