This function will convert the Well Known Text to JSON for ESRI Geometry creation. See example at http://jsfiddle.net/mac1175/6hcax/

Convert WKT to Json for ESRI JSAPI

function fromWKT2Json(WKTstr) {
    var mods = {};
    var convertToPointArray = function (ptArrayString) {
        var points = [],
            ptStringArray = ptArrayString.replace(/\)|\(/gi, "").split(",");
        ptStringArray.forEach(function (pt) {
           
            var splitpt = pt.trim().split(" "),
                x = parseFloat(splitpt[0], 10),
                y = parseFloat(splitpt[1], 10);

            points[points.length] = [x, y];
        });
        return points;
    };

    mods.POINT = function (tailStr) {
        ///point should be in the following format:
        //    (xxxx yyyy)
        console.log(tailStr);
        var point = tailStr.replace(/\)|\(/gi, "").trim().split(" ");
        return {
            type: 'point',
            x: parseFloat(point[0], 10),
            y: parseFloat(point[1], 10)
        };
    };
    mods.MULTILINESTRING = function (tailStr) {
        //should be in the following format:
        //    MULTILINESTRING((10 10, 20 20), (15 15, 30 15))
        ///strip outermost parenthesis
        tailStr = tailStr.replace(/(\(\()|(\)\))/gi, '');
        //split on tailing parenthesis and comma
        var paths = [],
            pathsRaw = tailStr.split("),"); ///show now have ['(x1 y1, x2 y2,....)','(x1 y1, x2 y2,....)',...]

        pathsRaw.forEach(function (p) {
            paths[paths.length] = convertToPointArray(p);

        });
        return {
            type: 'polyline',
            paths: paths
        };
    };

    mods.POLYGON = function (tailStr) {
        var ml = mods.MULTILINESTRING(tailStr);
        ///DIFFERENCES BETWEEN THIS AND MULTILINE IS THAT THE PATHS ARE RINGS 
        return {
            type: 'polygon',
            rings: ml.paths
        };
    };
    mods.MULTIPOLYGON = function (tailStr) {
        console.error('MULTIPOLYGON - not implemented');
    };
    mods.MULTIPOINT = function (tailStr) {
        return {
            type: 'multipoint',
            points: convertToPointArray(tailStr)
        };
    };
    mods.LINESTRING = function (tailStr) {
        //only close translation is multipoint
        return mods.MULTIPOINT(tailStr);

    };
    //chunk up the incoming geometry WKT  string
    var geoArray = WKTstr.split("("),
        head = geoArray.shift().trim(), ///head should be the geometry type
        tail = '(' + (geoArray.join("(").trim()); ///reconstitute the body

    return mods[head](tail);
}