It All Depends,
When speaking of short term I assume it means min. of 5 years. As in nowadays Dubai market, there's no big room for flipping anymore. Most of developers restrict flipping and 4% transfer fees makes everyone think twice before buying a (second hand -off plan property).
So I would break it down like this:
- As a short term : Rental yields will remain around 4-5% in most popular areas, 6-8% in eccentric areas like IMPZ or Dubai land. While sale prices will remain in the positive sides, in Dubai market, location matters to most End Users and this will keep the mature communities going while investors will start migrating to city border for higher yields.
- Med term: All over Dubai, all mature communities like DT, Emirates Living will start noticing of price drops as new supply floods the market late 2015 and 2016. End users will find more modern units for cheaper prices. Rentals in the mature communities will remain on growth, supported by corporate tenants( specially for small units ) while border areas will definitely rise supported by migration from expensive areas by non corporate tenants.
- Long Term ( 10 years): Market will face a correction movement again in Dubai based on qualifications of developers and demand of affordable accommodations. Considering Expo 2020 jobs supply, it will push a lot of demand in the market more towards affordable accommodation which will be around borders( Sport City, IMPZ, DIP, JVC).
Basically investment in Dubai now is kind of limited to off plan properties with fair payment plans. Investors tend more toward this direction as a guaranteed form of investment in selected projected either by location or quality.
hope this helps!