Citrix have recently released a hotfix to XenApp (HRP04) that allows their Branch Repeater products to cache certain aspects of ICA across users sessions.
Now, I would imagine only a tiny fraction of XenApp customers are using both XenApp and the Branch Repeater, meaning very few actually benefit.
Far more customers will be use a competitors WAN acceleration product (F5, RiverBed etc) and are very unlikely to rip out perfectly good technology to buy a Branch Repeater.
My call to Citrix is to open up the enhancements you have made to ICA and allow these thirdy parties to add support for caching and accelerating ICA.
Keeping this closed to your chest isn't going to sell any more Branch Repeaters, but allowing the existing WAN Acceleration vendors to accelerate ICA will benefit many of your existing XenApp customers.