TPM will probably not earn $ 100 million during its opening weekend. From May 21 to 23, TPM will likely earn somewhere between $ 65 to 75 million. TPM will be released in only about 2,400 theaters. This is small compared to the 6,000 plus screens that Godzilla was lauched on last Memorial Day Weekend.
If TPM proves to be a great movie, then it may earn over $ 100 million during the four day Memorial Day Weekend (its second weekend of release). But don't bet on it . . .
One problem you may face on opening weekend is people sneaking it to TPM exhibition room. If this happens, some people may not be able to find a seat if TPM is as popular as expected. Make sure you arrive at the theater early so you can reserve a seat. That way you want have to stand for over 2 hours while watching TPM. It is almost inevitable that there will be people sneaking in to watch TPM during its intial weekend. May the Force be with you!