They will definately go up, but they will not surpass the LLL.COM in value. This is of coarse for equivalent domains. SEX.NET will always be worth more then QUZ.COM however the equivalent domain SEX.COM will always be more then SEX.NET
Depends on what your definition of "good value" is & depends on what those LLL's are. Absolutely, but they'll never be worth the same or more than the same .com equivalant.