To be honest, there is not really a lot of options. The biggest land space they have to accommodate rides is of course Maloney's Corner behind Coney Island. This would be the most obvious choice to install a new coaster or attraction. Of course , this depends on the size of the coaster installed and where they could relocate the other rides that may be displaced by this coaster.
The only real options that I could see are:
Move the Tumblebug to the Flying Saucer site ( that's on the assumption that this space will be able to accommodate this large ride). This then would leave the space where the Tumblebug currently resides for another attraction- this space could be big enough to fit in a new compact coaster. This is currently vastly under utilised space by LPS and if they do not install another coaster here, could easily fit 2 medium sized flats.
There is an area that is currently an open space environment that sits above the ticket office and the car park entrance. It is currently a green area but it could be converted to a kids ride area with access to the park below coming down near where the Light House stands. This then would free up more space in Maloney's Corner to develop into new attractions.
The above pic, whilst not a great resolution, is from 2005. It shows the relative position of the offices behind the Flying Saucer site and the Tango Train. A coaster that runs parallel behind Coney Island is of course a possibility and depending on the size, would not displace the Moon Ranger or Spider.
Here in this 1995 pic, it shows exactly how much real estate the Big Top actually takes up, starting from the end of the Tango and adjoining the Big Dipper entrance.
For mine, a real positive step would be to re-install the ride facades that were present from the '95 incarnation. They gave the park an old world feel and gave the rides a unique and distinctive look.
The possibility of LPS getting another large coaster, let alone ANY coaster, is fairly slim IMHO. There are plenty of compacts out there that of course could remain a distinct possibility and given some creative thinking, could feature in LPS's future. As always, I have my fingers crossed!