For 94 beta1, code blocks are not supported for VbScript in the GP CalculateField tool or by right clicking a field in TableView. That is due to the deprecation of VBA of 94. At 93, multiline VB code blocks were actually parsed by VBA, and the single line expression parameter was parsed by VbScript. We do however still support VbScript at 94; but it still only for the single line expression parameter. We are currently investigating VbScript code blocks for 94 to support 93 workflows. For your records, the tracking number to support multiline code blocks in NIM050827.
At beta1, you have to use Python for complex code blocks.
Please let me know if you have any questions about this, or if you run in to any other problems with the 94 field calculator; especially any issues with transitioning 93 workflows to 94.