OVH now offer hosting packages for almost anyone using almost every hypervisor !
vps
entry level dedicated
enterprise dedicated
mini cloud
DIY cloud (using your choice of - kvm, openvz, proxmox, vmw, xen)
Red Hat RHEL 5.7 has increased virtualisation speed for KVM and XEN
rpath X6 supported hypervisors and virtual targets
HP, IBM and KVM have created the Open Virtualisation Alliance which will foster the adoption of KVM as an enterprise-ready open virtualization solution.
Other members include Intel, Red Hat and Novell Suse.
cheapvps.co.uk provide KVM, OpenVZ and XEN hosting !
XenSource have a directory of XEN webhosts
and there is a searchable list of XEN and other webhosts at VPSChoice !
CloudMin can help you manage KVM, OpenVZ and Xen clouds.
VirtualMin have also made available some VirtualMin & EC2 AMIs you can try out for yourself.
http://www.virtualmin.com/documentation/aws/virtualmin_gpl_ami/
According to The Register Red Hat are replacing Xen with KVM in RHEL 6 !
One of the main goals for RHEL 6 was to make managing virtual servers as easy as managing physical machines, which means the bulk of the new software features are found in KVM. It also means that Xen is gone, though that’s hardly surprising since Red Hat purchased Qumranet – creators of KVM – back in 2008.
Red Hat RHEL VIrtualisation Webinars
The latest announcement from Red Hat about Red Hat Enterprise Virtualization for Servers says Red Hat Enterprise Virtualization features a unique and revolutionary virtualisation technology called KVM and that they have virtualised a workload of 12.5 VM’s per core (ie 400 VM’s) using a 32 core 1TB server ! And unlike Oracle Xen VM Server, Red Hat Enterprise Virtualization, includes SELinux secuirty technology !