There will always be people that want to borrow money, and there will always be people who are willing to lend money for a fee. What will not continue is Fractional Reserve Lending because it is predicated upon the necessity of people having no choice but to deposit their funds in banks and the impracticality of proof of solvency.
With bitcoin there is no need to deposit your bitcoins in a bank and even if you do, you now have the choice to only deposit your bitcoins in a bank that allow for full Proof of Solvency so you know for sure that your bitcoins are safe in sound and not being lent to low income borrowers with no job no credit or bad credit, and not being gambled on bad bets in the stock market.
This does not mean that there will be no more loans. Just look on this very forum there are people offering loans. Loans will still exist they will only exist in a more honest fashion, which is to say that lenders will be those who have excess capitol they are able to lend, instead of promising to keep your money safe and turning around and lending your money to people. Lenders will will have to be those who lend their own money, not those who lend other people's money. And I think that is a more honest system for the economy to be based on.
What kind of legal measures could someone take if the borrower defaults on a loan? And if there are none why would people lend?