For the existing installation to upgrade would be SAP NW 7.03 and for the standalone or isolated fresh installations will be based on SAP NW 7.3x
The application upgrade will (for example SRM 7.0x, CRM 7.0x, SCM 7.0x, ERP 6.06 or so) could be based on the SAP NW 7.03. Also the latest release adaptability possible.
However fresh installation will have baseline of SAP NW 7.3x
As SAP is shipping the business suite's new releases based on the 7.3 platform, existing customer needs to plan their future landscapes based on their business strategy.
Customers planning for the near future upgrade to SAP SRM
7.0x, please utilise SAP Solution Manager tool to optimize the landscape and seek the
advice from an SAP NetWeaver architect.