If I were Mark T, I would
1. Protect my 'used-to-be-loyal, but now-sorta-fickle' install base -- get everyone to the latest and greatest version of XD/XA. Make them less vulnerable to VMware
2. Go after new accounts in verticals -- healthcare, education, government sector, financial services, etc -- working with infrastructure vendors like the big boys (Cisco, HP, Dell, Lenovo, EMC, etc) and upstarts (Nimble, Nutanix, etc)
3. Kill XenServers -- as much as this would pain Citrix XenServer is done. Don't let it distract.
4. Invest in cloud services -- AWS style services (everyone is on the go).