When done correctly, “Secure Boot” is designed to protect against malware by preventing computers from loading unauthorized binary programs when booting. In practice, this means that computers implementing it won’t boot unauthorized operating systems — including initially authorized systems that have been modified without being re-approved.
The biggest issue with the “Secure Boot” system, is that it’ll create a vendor-lockin. This has been seen with the android system as well, but it’ll be Microsft pulling the strings on this one.
Some other interesting reads on Secure Boot: