whats so difficult at holding down CTRL while clicking on a link?
i have a better question why not do it? the pros include for me anyways are that I don't have to log in every time I accidentally press a link without using control. the other thing is most other sites follow the opposite format and move links to a separate tab. meaning i now have to adjust to a new format for just one site. (at-least that ive been on.) on top of that quite a few people have already asked/complained/been confused about this saying its inconvenient or don't know how to open the link to a new page leading to someone having to explain to them how to do it. which tells me this thing isn't exactly common knowledge.
so instead of stonewalling/mocking/playing games with your forumites. why don't you man up and answer the question of why you don't want to do this?
heres a solution i came up with that caters to both sides of the isle.
provide a check box allowing users to choose if they want there links to open to over existing window a new tab or a new window.