WBS的provisional offer？

哪位前辈或者同志也收到过 provisional offer呢？
WARWICK的WBS 给我发了个 provisional offer，我很困惑这个东东的意义，不知和正式的offer有什么区别？收到这个再拿到正式offer的机率又是多少？没拿到正式的offer始终不放心啊。
上面说：
Further to your application for the above programme, I am pleased to inform you that I am recommending to the University Higher Degrees Committee that you be offered a place on the course for the academic year 2006/2007.  Please note that my offer is provisional, the final decision will be made by the University’s Higher Degrees Committee and should they approve my recommendation, a letter from the University’s Graduate Office will be sent to you, this will set out details of your offer, the fees and accommodation.
后面就是一些注意事项和希望我接受的话。
我申的是WBS的 MSC INFORMATION SYSTEMS & MANAGEMENT
哪位高人能指点一下，先谢过了。