[bogomipz]

If its stateless traffic then yes.

The ECMP/Anycast just gets you beyond the limit of an single pair of IPVS boxes which are are kept in sync with keepalived/vrrp for HA.

But a pair of boxes with ipvs + keepalived + iptables should be be able to handle a few thousand connections no problems. Your concern would then likely be the bandwidth going through the box. But if your client pull rather than push using direct server return should be able to get you past the bandwidth limitations of a single box.