Cloud acceleration is one form of delivering web content and applications as quickly as possible. Cloud acceleration is similar to a content delivery network, or CDN, in that it attempts to get content to users as quickly as possible. While CDNs rely on edge caching, cloud acceleration optimizes the delivery path and routes content through public or private, managed networks
Trend: Cloud acceleration and CDN networks are not mutually exclusive--both are very important. In fact, both are complementary to achieving a goal of delivering data between a user and a server/cloud in the fastest possible way. One of the biggest hindrances to network performance speed is the geographic distance from the one's computer (the IP source) to a remote computer where the content resides (the IP destination). For example, a client in Washington D.C. would have to go 231 miles to retrieve data from a server in New York. Today, as more and more IT infrastructures are being migrated to the cloud (typically in a remote region), geographic distance is increased with people around the world accessing cloud infrastructures halfway across the world from them. As we all know, the longer the distance, the higher the network latency and slower the application performance.
A CDN solution fixes this problem for static content (web pages, videos, pictures, etc.) because the CDN distributes and caches the same static content around the world so that it could be "served" up as close to the user as possible. But, what about dynamic content that constantly changes, such as sharepoint, CRM applications, or most cloud applications (SaaS, PaaS, etc.), etc? Since this content is dynamically changing, it cannot be distributed and cached. Instead, the client must still traverse the global distance to retrieve content. Latency remains the issue.
This is where Cloud Acceleration comes in. Cloud acceleration solves the problem of distance by making the globally traversed connection more "efficient" between a client and remote server. What do I mean by "efficiency?" Network efficiency is achieved by decreasing the amount of duplicated data that is transmitted back and forth between a client and a remote server, optimizing the TCP protocol, and mitigating the chattiness of inefficient applications. 
- Cloud Computing Journal, Next Generation Content Delivery: Cloud Acceleration, By Jonathan Hoppe Jul. 22, 2010 http://cloudcomputing.sys-con.com/node/1471257
- By Henry Chan, CCIE#6843