Hi,
On the Nexus 7000 we're able to have both routers forwarding for an HSRP group. This was first introduced with Cisco virtual Port Channel (vPC) on this platform and is also available with FabricPath. There is still the concept of an active and standby router from a control perspective, but both routers are able to perform traffic forwarding.
The way this is acheive is via a vPC+ domain configured on the Nexus 7000 aggregation layer routers. As per the Cisco FabricPath Design Guide: Using FabricPath with an Aggregation and Access Topology:
Because of this switch-id configuration, HSRP, VRRP, and GLBP announce their vMAC as coming from the emulated switch-id instead of the switch-id of each individual spine. By doing this, the edge switches can forward HSRP frames to either spine.
On both spines, the HSRP MAC address is programmed in the MAC tables with the special flag (G-flag) that indicates that this traffic is meant to be routed.
The concept is discussed in the Gateway Routing section of the FabricPath design guide.
Where there is benefit to using GLBP in Nexus FabricPath designs is when using a topology with greater than two FabricPath spine switches. As GLBP is able to support four active forwarders, FabricPath designs where there are four spine switches would benefit from GLBP.
Regards
